| /* |
| * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com |
| * Written by Alex Tomas <alex@clusterfs.com> |
| * |
| * Architecture independence: |
| * Copyright (c) 2005, Bull S.A. |
| * Written by Pierre Peiffer <pierre.peiffer@bull.net> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- |
| */ |
| |
| /* |
| * Extents support for EXT4 |
| * |
| * TODO: |
| * - ext4*_error() should be used in some situations |
| * - analyze all BUG()/BUG_ON(), use -EIO where appropriate |
| * - smart tree reduction |
| */ |
| |
| #include <linux/fs.h> |
| #include <linux/time.h> |
| #include <linux/jbd2.h> |
| #include <linux/highuid.h> |
| #include <linux/pagemap.h> |
| #include <linux/quotaops.h> |
| #include <linux/string.h> |
| #include <linux/slab.h> |
| #include <asm/uaccess.h> |
| #include <linux/fiemap.h> |
| #include <linux/backing-dev.h> |
| #include "ext4_jbd2.h" |
| #include "ext4_extents.h" |
| #include "xattr.h" |
| |
| #include <trace/events/ext4.h> |
| |
| /* |
| * used by extent splitting. |
| */ |
| #define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \ |
| due to ENOSPC */ |
| #define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */ |
| #define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */ |
| |
| #define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */ |
| #define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */ |
| |
| static __le32 ext4_extent_block_csum(struct inode *inode, |
| struct ext4_extent_header *eh) |
| { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| __u32 csum; |
| |
| csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh, |
| EXT4_EXTENT_TAIL_OFFSET(eh)); |
| return cpu_to_le32(csum); |
| } |
| |
| static int ext4_extent_block_csum_verify(struct inode *inode, |
| struct ext4_extent_header *eh) |
| { |
| struct ext4_extent_tail *et; |
| |
| if (!ext4_has_metadata_csum(inode->i_sb)) |
| return 1; |
| |
| et = find_ext4_extent_tail(eh); |
| if (et->et_checksum != ext4_extent_block_csum(inode, eh)) |
| return 0; |
| return 1; |
| } |
| |
| static void ext4_extent_block_csum_set(struct inode *inode, |
| struct ext4_extent_header *eh) |
| { |
| struct ext4_extent_tail *et; |
| |
| if (!ext4_has_metadata_csum(inode->i_sb)) |
| return; |
| |
| et = find_ext4_extent_tail(eh); |
| et->et_checksum = ext4_extent_block_csum(inode, eh); |
| } |
| |
| static int ext4_split_extent(handle_t *handle, |
| struct inode *inode, |
| struct ext4_ext_path **ppath, |
| struct ext4_map_blocks *map, |
| int split_flag, |
| int flags); |
| |
| static int ext4_split_extent_at(handle_t *handle, |
| struct inode *inode, |
| struct ext4_ext_path **ppath, |
| ext4_lblk_t split, |
| int split_flag, |
| int flags); |
| |
| static int ext4_find_delayed_extent(struct inode *inode, |
| struct extent_status *newes); |
| |
| static int ext4_ext_truncate_extend_restart(handle_t *handle, |
| struct inode *inode, |
| int needed) |
| { |
| int err; |
| |
| if (!ext4_handle_valid(handle)) |
| return 0; |
| if (handle->h_buffer_credits >= needed) |
| return 0; |
| /* |
| * If we need to extend the journal get a few extra blocks |
| * while we're at it for efficiency's sake. |
| */ |
| needed += 3; |
| err = ext4_journal_extend(handle, needed - handle->h_buffer_credits); |
| if (err <= 0) |
| return err; |
| err = ext4_truncate_restart_trans(handle, inode, needed); |
| if (err == 0) |
| err = -EAGAIN; |
| |
| return err; |
| } |
| |
| /* |
| * could return: |
| * - EROFS |
| * - ENOMEM |
| */ |
| static int ext4_ext_get_access(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| if (path->p_bh) { |
| /* path points to block */ |
| BUFFER_TRACE(path->p_bh, "get_write_access"); |
| return ext4_journal_get_write_access(handle, path->p_bh); |
| } |
| /* path points to leaf/index in inode body */ |
| /* we use in-core data, no need to protect them */ |
| return 0; |
| } |
| |
| /* |
| * could return: |
| * - EROFS |
| * - ENOMEM |
| * - EIO |
| */ |
| int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle, |
| struct inode *inode, struct ext4_ext_path *path) |
| { |
| int err; |
| |
| WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem)); |
| if (path->p_bh) { |
| ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh)); |
| /* path points to block */ |
| err = __ext4_handle_dirty_metadata(where, line, handle, |
| inode, path->p_bh); |
| } else { |
| /* path points to leaf/index in inode body */ |
| err = ext4_mark_inode_dirty(handle, inode); |
| } |
| return err; |
| } |
| |
| static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, |
| struct ext4_ext_path *path, |
| ext4_lblk_t block) |
| { |
| if (path) { |
| int depth = path->p_depth; |
| struct ext4_extent *ex; |
| |
| /* |
| * Try to predict block placement assuming that we are |
| * filling in a file which will eventually be |
| * non-sparse --- i.e., in the case of libbfd writing |
| * an ELF object sections out-of-order but in a way |
| * the eventually results in a contiguous object or |
| * executable file, or some database extending a table |
| * space file. However, this is actually somewhat |
| * non-ideal if we are writing a sparse file such as |
| * qemu or KVM writing a raw image file that is going |
| * to stay fairly sparse, since it will end up |
| * fragmenting the file system's free space. Maybe we |
| * should have some hueristics or some way to allow |
| * userspace to pass a hint to file system, |
| * especially if the latter case turns out to be |
| * common. |
| */ |
| ex = path[depth].p_ext; |
| if (ex) { |
| ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex); |
| ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block); |
| |
| if (block > ext_block) |
| return ext_pblk + (block - ext_block); |
| else |
| return ext_pblk - (ext_block - block); |
| } |
| |
| /* it looks like index is empty; |
| * try to find starting block from index itself */ |
| if (path[depth].p_bh) |
| return path[depth].p_bh->b_blocknr; |
| } |
| |
| /* OK. use inode's group */ |
| return ext4_inode_to_goal_block(inode); |
| } |
| |
| /* |
| * Allocation for a meta data block |
| */ |
| static ext4_fsblk_t |
| ext4_ext_new_meta_block(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *ex, int *err, unsigned int flags) |
| { |
| ext4_fsblk_t goal, newblock; |
| |
| goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); |
| newblock = ext4_new_meta_blocks(handle, inode, goal, flags, |
| NULL, err); |
| return newblock; |
| } |
| |
| static inline int ext4_ext_space_block(struct inode *inode, int check) |
| { |
| int size; |
| |
| size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) |
| / sizeof(struct ext4_extent); |
| #ifdef AGGRESSIVE_TEST |
| if (!check && size > 6) |
| size = 6; |
| #endif |
| return size; |
| } |
| |
| static inline int ext4_ext_space_block_idx(struct inode *inode, int check) |
| { |
| int size; |
| |
| size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) |
| / sizeof(struct ext4_extent_idx); |
| #ifdef AGGRESSIVE_TEST |
| if (!check && size > 5) |
| size = 5; |
| #endif |
| return size; |
| } |
| |
| static inline int ext4_ext_space_root(struct inode *inode, int check) |
| { |
| int size; |
| |
| size = sizeof(EXT4_I(inode)->i_data); |
| size -= sizeof(struct ext4_extent_header); |
| size /= sizeof(struct ext4_extent); |
| #ifdef AGGRESSIVE_TEST |
| if (!check && size > 3) |
| size = 3; |
| #endif |
| return size; |
| } |
| |
| static inline int ext4_ext_space_root_idx(struct inode *inode, int check) |
| { |
| int size; |
| |
| size = sizeof(EXT4_I(inode)->i_data); |
| size -= sizeof(struct ext4_extent_header); |
| size /= sizeof(struct ext4_extent_idx); |
| #ifdef AGGRESSIVE_TEST |
| if (!check && size > 4) |
| size = 4; |
| #endif |
| return size; |
| } |
| |
| static inline int |
| ext4_force_split_extent_at(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path **ppath, ext4_lblk_t lblk, |
| int nofail) |
| { |
| struct ext4_ext_path *path = *ppath; |
| int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext); |
| |
| return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ? |
| EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0, |
| EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO | |
| (nofail ? EXT4_GET_BLOCKS_METADATA_NOFAIL:0)); |
| } |
| |
| /* |
| * Calculate the number of metadata blocks needed |
| * to allocate @blocks |
| * Worse case is one block per extent |
| */ |
| int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock) |
| { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| int idxs; |
| |
| idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) |
| / sizeof(struct ext4_extent_idx)); |
| |
| /* |
| * If the new delayed allocation block is contiguous with the |
| * previous da block, it can share index blocks with the |
| * previous block, so we only need to allocate a new index |
| * block every idxs leaf blocks. At ldxs**2 blocks, we need |
| * an additional index block, and at ldxs**3 blocks, yet |
| * another index blocks. |
| */ |
| if (ei->i_da_metadata_calc_len && |
| ei->i_da_metadata_calc_last_lblock+1 == lblock) { |
| int num = 0; |
| |
| if ((ei->i_da_metadata_calc_len % idxs) == 0) |
| num++; |
| if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0) |
| num++; |
| if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) { |
| num++; |
| ei->i_da_metadata_calc_len = 0; |
| } else |
| ei->i_da_metadata_calc_len++; |
| ei->i_da_metadata_calc_last_lblock++; |
| return num; |
| } |
| |
| /* |
| * In the worst case we need a new set of index blocks at |
| * every level of the inode's extent tree. |
| */ |
| ei->i_da_metadata_calc_len = 1; |
| ei->i_da_metadata_calc_last_lblock = lblock; |
| return ext_depth(inode) + 1; |
| } |
| |
| static int |
| ext4_ext_max_entries(struct inode *inode, int depth) |
| { |
| int max; |
| |
| if (depth == ext_depth(inode)) { |
| if (depth == 0) |
| max = ext4_ext_space_root(inode, 1); |
| else |
| max = ext4_ext_space_root_idx(inode, 1); |
| } else { |
| if (depth == 0) |
| max = ext4_ext_space_block(inode, 1); |
| else |
| max = ext4_ext_space_block_idx(inode, 1); |
| } |
| |
| return max; |
| } |
| |
| static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) |
| { |
| ext4_fsblk_t block = ext4_ext_pblock(ext); |
| int len = ext4_ext_get_actual_len(ext); |
| ext4_lblk_t lblock = le32_to_cpu(ext->ee_block); |
| |
| /* |
| * We allow neither: |
| * - zero length |
| * - overflow/wrap-around |
| */ |
| if (lblock + len <= lblock) |
| return 0; |
| return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); |
| } |
| |
| static int ext4_valid_extent_idx(struct inode *inode, |
| struct ext4_extent_idx *ext_idx) |
| { |
| ext4_fsblk_t block = ext4_idx_pblock(ext_idx); |
| |
| return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1); |
| } |
| |
| static int ext4_valid_extent_entries(struct inode *inode, |
| struct ext4_extent_header *eh, |
| int depth) |
| { |
| unsigned short entries; |
| if (eh->eh_entries == 0) |
| return 1; |
| |
| entries = le16_to_cpu(eh->eh_entries); |
| |
| if (depth == 0) { |
| /* leaf entries */ |
| struct ext4_extent *ext = EXT_FIRST_EXTENT(eh); |
| struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es; |
| ext4_fsblk_t pblock = 0; |
| ext4_lblk_t lblock = 0; |
| ext4_lblk_t prev = 0; |
| int len = 0; |
| while (entries) { |
| if (!ext4_valid_extent(inode, ext)) |
| return 0; |
| |
| /* Check for overlapping extents */ |
| lblock = le32_to_cpu(ext->ee_block); |
| len = ext4_ext_get_actual_len(ext); |
| if ((lblock <= prev) && prev) { |
| pblock = ext4_ext_pblock(ext); |
| es->s_last_error_block = cpu_to_le64(pblock); |
| return 0; |
| } |
| ext++; |
| entries--; |
| prev = lblock + len - 1; |
| } |
| } else { |
| struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh); |
| while (entries) { |
| if (!ext4_valid_extent_idx(inode, ext_idx)) |
| return 0; |
| ext_idx++; |
| entries--; |
| } |
| } |
| return 1; |
| } |
| |
| static int __ext4_ext_check(const char *function, unsigned int line, |
| struct inode *inode, struct ext4_extent_header *eh, |
| int depth, ext4_fsblk_t pblk) |
| { |
| const char *error_msg; |
| int max = 0, err = -EFSCORRUPTED; |
| |
| if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { |
| error_msg = "invalid magic"; |
| goto corrupted; |
| } |
| if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { |
| error_msg = "unexpected eh_depth"; |
| goto corrupted; |
| } |
| if (unlikely(eh->eh_max == 0)) { |
| error_msg = "invalid eh_max"; |
| goto corrupted; |
| } |
| max = ext4_ext_max_entries(inode, depth); |
| if (unlikely(le16_to_cpu(eh->eh_max) > max)) { |
| error_msg = "too large eh_max"; |
| goto corrupted; |
| } |
| if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { |
| error_msg = "invalid eh_entries"; |
| goto corrupted; |
| } |
| if (!ext4_valid_extent_entries(inode, eh, depth)) { |
| error_msg = "invalid extent entries"; |
| goto corrupted; |
| } |
| if (unlikely(depth > 32)) { |
| error_msg = "too large eh_depth"; |
| goto corrupted; |
| } |
| /* Verify checksum on non-root extent tree nodes */ |
| if (ext_depth(inode) != depth && |
| !ext4_extent_block_csum_verify(inode, eh)) { |
| error_msg = "extent tree corrupted"; |
| err = -EFSBADCRC; |
| goto corrupted; |
| } |
| return 0; |
| |
| corrupted: |
| ext4_error_inode(inode, function, line, 0, |
| "pblk %llu bad header/extent: %s - magic %x, " |
| "entries %u, max %u(%u), depth %u(%u)", |
| (unsigned long long) pblk, error_msg, |
| le16_to_cpu(eh->eh_magic), |
| le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), |
| max, le16_to_cpu(eh->eh_depth), depth); |
| return err; |
| } |
| |
| #define ext4_ext_check(inode, eh, depth, pblk) \ |
| __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk)) |
| |
| int ext4_ext_check_inode(struct inode *inode) |
| { |
| return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0); |
| } |
| |
| static struct buffer_head * |
| __read_extent_tree_block(const char *function, unsigned int line, |
| struct inode *inode, ext4_fsblk_t pblk, int depth, |
| int flags) |
| { |
| struct buffer_head *bh; |
| int err; |
| |
| bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS); |
| if (unlikely(!bh)) |
| return ERR_PTR(-ENOMEM); |
| |
| if (!bh_uptodate_or_lock(bh)) { |
| trace_ext4_ext_load_extent(inode, pblk, _RET_IP_); |
| err = bh_submit_read(bh); |
| if (err < 0) |
| goto errout; |
| } |
| if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE)) |
| return bh; |
| err = __ext4_ext_check(function, line, inode, |
| ext_block_hdr(bh), depth, pblk); |
| if (err) |
| goto errout; |
| set_buffer_verified(bh); |
| /* |
| * If this is a leaf block, cache all of its entries |
| */ |
| if (!(flags & EXT4_EX_NOCACHE) && depth == 0) { |
| struct ext4_extent_header *eh = ext_block_hdr(bh); |
| struct ext4_extent *ex = EXT_FIRST_EXTENT(eh); |
| ext4_lblk_t prev = 0; |
| int i; |
| |
| for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) { |
| unsigned int status = EXTENT_STATUS_WRITTEN; |
| ext4_lblk_t lblk = le32_to_cpu(ex->ee_block); |
| int len = ext4_ext_get_actual_len(ex); |
| |
| if (prev && (prev != lblk)) |
| ext4_es_cache_extent(inode, prev, |
| lblk - prev, ~0, |
| EXTENT_STATUS_HOLE); |
| |
| if (ext4_ext_is_unwritten(ex)) |
| status = EXTENT_STATUS_UNWRITTEN; |
| ext4_es_cache_extent(inode, lblk, len, |
| ext4_ext_pblock(ex), status); |
| prev = lblk + len; |
| } |
| } |
| return bh; |
| errout: |
| put_bh(bh); |
| return ERR_PTR(err); |
| |
| } |
| |
| #define read_extent_tree_block(inode, pblk, depth, flags) \ |
| __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \ |
| (depth), (flags)) |
| |
| /* |
| * This function is called to cache a file's extent information in the |
| * extent status tree |
| */ |
| int ext4_ext_precache(struct inode *inode) |
| { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| struct ext4_ext_path *path = NULL; |
| struct buffer_head *bh; |
| int i = 0, depth, ret = 0; |
| |
| if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) |
| return 0; /* not an extent-mapped inode */ |
| |
| down_read(&ei->i_data_sem); |
| depth = ext_depth(inode); |
| |
| path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), |
| GFP_NOFS); |
| if (path == NULL) { |
| up_read(&ei->i_data_sem); |
| return -ENOMEM; |
| } |
| |
| /* Don't cache anything if there are no external extent blocks */ |
| if (depth == 0) |
| goto out; |
| path[0].p_hdr = ext_inode_hdr(inode); |
| ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0); |
| if (ret) |
| goto out; |
| path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr); |
| while (i >= 0) { |
| /* |
| * If this is a leaf block or we've reached the end of |
| * the index block, go up |
| */ |
| if ((i == depth) || |
| path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) { |
| brelse(path[i].p_bh); |
| path[i].p_bh = NULL; |
| i--; |
| continue; |
| } |
| bh = read_extent_tree_block(inode, |
| ext4_idx_pblock(path[i].p_idx++), |
| depth - i - 1, |
| EXT4_EX_FORCE_CACHE); |
| if (IS_ERR(bh)) { |
| ret = PTR_ERR(bh); |
| break; |
| } |
| i++; |
| path[i].p_bh = bh; |
| path[i].p_hdr = ext_block_hdr(bh); |
| path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr); |
| } |
| ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED); |
| out: |
| up_read(&ei->i_data_sem); |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| return ret; |
| } |
| |
| #ifdef EXT_DEBUG |
| static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) |
| { |
| int k, l = path->p_depth; |
| |
| ext_debug("path:"); |
| for (k = 0; k <= l; k++, path++) { |
| if (path->p_idx) { |
| ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), |
| ext4_idx_pblock(path->p_idx)); |
| } else if (path->p_ext) { |
| ext_debug(" %d:[%d]%d:%llu ", |
| le32_to_cpu(path->p_ext->ee_block), |
| ext4_ext_is_unwritten(path->p_ext), |
| ext4_ext_get_actual_len(path->p_ext), |
| ext4_ext_pblock(path->p_ext)); |
| } else |
| ext_debug(" []"); |
| } |
| ext_debug("\n"); |
| } |
| |
| static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) |
| { |
| int depth = ext_depth(inode); |
| struct ext4_extent_header *eh; |
| struct ext4_extent *ex; |
| int i; |
| |
| if (!path) |
| return; |
| |
| eh = path[depth].p_hdr; |
| ex = EXT_FIRST_EXTENT(eh); |
| |
| ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino); |
| |
| for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { |
| ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block), |
| ext4_ext_is_unwritten(ex), |
| ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); |
| } |
| ext_debug("\n"); |
| } |
| |
| static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path, |
| ext4_fsblk_t newblock, int level) |
| { |
| int depth = ext_depth(inode); |
| struct ext4_extent *ex; |
| |
| if (depth != level) { |
| struct ext4_extent_idx *idx; |
| idx = path[level].p_idx; |
| while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) { |
| ext_debug("%d: move %d:%llu in new index %llu\n", level, |
| le32_to_cpu(idx->ei_block), |
| ext4_idx_pblock(idx), |
| newblock); |
| idx++; |
| } |
| |
| return; |
| } |
| |
| ex = path[depth].p_ext; |
| while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) { |
| ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n", |
| le32_to_cpu(ex->ee_block), |
| ext4_ext_pblock(ex), |
| ext4_ext_is_unwritten(ex), |
| ext4_ext_get_actual_len(ex), |
| newblock); |
| ex++; |
| } |
| } |
| |
| #else |
| #define ext4_ext_show_path(inode, path) |
| #define ext4_ext_show_leaf(inode, path) |
| #define ext4_ext_show_move(inode, path, newblock, level) |
| #endif |
| |
| void ext4_ext_drop_refs(struct ext4_ext_path *path) |
| { |
| int depth, i; |
| |
| if (!path) |
| return; |
| depth = path->p_depth; |
| for (i = 0; i <= depth; i++, path++) |
| if (path->p_bh) { |
| brelse(path->p_bh); |
| path->p_bh = NULL; |
| } |
| } |
| |
| /* |
| * ext4_ext_binsearch_idx: |
| * binary search for the closest index of the given block |
| * the header must be checked before calling this |
| */ |
| static void |
| ext4_ext_binsearch_idx(struct inode *inode, |
| struct ext4_ext_path *path, ext4_lblk_t block) |
| { |
| struct ext4_extent_header *eh = path->p_hdr; |
| struct ext4_extent_idx *r, *l, *m; |
| |
| |
| ext_debug("binsearch for %u(idx): ", block); |
| |
| l = EXT_FIRST_INDEX(eh) + 1; |
| r = EXT_LAST_INDEX(eh); |
| while (l <= r) { |
| m = l + (r - l) / 2; |
| if (block < le32_to_cpu(m->ei_block)) |
| r = m - 1; |
| else |
| l = m + 1; |
| ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block), |
| m, le32_to_cpu(m->ei_block), |
| r, le32_to_cpu(r->ei_block)); |
| } |
| |
| path->p_idx = l - 1; |
| ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block), |
| ext4_idx_pblock(path->p_idx)); |
| |
| #ifdef CHECK_BINSEARCH |
| { |
| struct ext4_extent_idx *chix, *ix; |
| int k; |
| |
| chix = ix = EXT_FIRST_INDEX(eh); |
| for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { |
| if (k != 0 && |
| le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { |
| printk(KERN_DEBUG "k=%d, ix=0x%p, " |
| "first=0x%p\n", k, |
| ix, EXT_FIRST_INDEX(eh)); |
| printk(KERN_DEBUG "%u <= %u\n", |
| le32_to_cpu(ix->ei_block), |
| le32_to_cpu(ix[-1].ei_block)); |
| } |
| BUG_ON(k && le32_to_cpu(ix->ei_block) |
| <= le32_to_cpu(ix[-1].ei_block)); |
| if (block < le32_to_cpu(ix->ei_block)) |
| break; |
| chix = ix; |
| } |
| BUG_ON(chix != path->p_idx); |
| } |
| #endif |
| |
| } |
| |
| /* |
| * ext4_ext_binsearch: |
| * binary search for closest extent of the given block |
| * the header must be checked before calling this |
| */ |
| static void |
| ext4_ext_binsearch(struct inode *inode, |
| struct ext4_ext_path *path, ext4_lblk_t block) |
| { |
| struct ext4_extent_header *eh = path->p_hdr; |
| struct ext4_extent *r, *l, *m; |
| |
| if (eh->eh_entries == 0) { |
| /* |
| * this leaf is empty: |
| * we get such a leaf in split/add case |
| */ |
| return; |
| } |
| |
| ext_debug("binsearch for %u: ", block); |
| |
| l = EXT_FIRST_EXTENT(eh) + 1; |
| r = EXT_LAST_EXTENT(eh); |
| |
| while (l <= r) { |
| m = l + (r - l) / 2; |
| if (block < le32_to_cpu(m->ee_block)) |
| r = m - 1; |
| else |
| l = m + 1; |
| ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block), |
| m, le32_to_cpu(m->ee_block), |
| r, le32_to_cpu(r->ee_block)); |
| } |
| |
| path->p_ext = l - 1; |
| ext_debug(" -> %d:%llu:[%d]%d ", |
| le32_to_cpu(path->p_ext->ee_block), |
| ext4_ext_pblock(path->p_ext), |
| ext4_ext_is_unwritten(path->p_ext), |
| ext4_ext_get_actual_len(path->p_ext)); |
| |
| #ifdef CHECK_BINSEARCH |
| { |
| struct ext4_extent *chex, *ex; |
| int k; |
| |
| chex = ex = EXT_FIRST_EXTENT(eh); |
| for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { |
| BUG_ON(k && le32_to_cpu(ex->ee_block) |
| <= le32_to_cpu(ex[-1].ee_block)); |
| if (block < le32_to_cpu(ex->ee_block)) |
| break; |
| chex = ex; |
| } |
| BUG_ON(chex != path->p_ext); |
| } |
| #endif |
| |
| } |
| |
| int ext4_ext_tree_init(handle_t *handle, struct inode *inode) |
| { |
| struct ext4_extent_header *eh; |
| |
| eh = ext_inode_hdr(inode); |
| eh->eh_depth = 0; |
| eh->eh_entries = 0; |
| eh->eh_magic = EXT4_EXT_MAGIC; |
| eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); |
| ext4_mark_inode_dirty(handle, inode); |
| return 0; |
| } |
| |
| struct ext4_ext_path * |
| ext4_find_extent(struct inode *inode, ext4_lblk_t block, |
| struct ext4_ext_path **orig_path, int flags) |
| { |
| struct ext4_extent_header *eh; |
| struct buffer_head *bh; |
| struct ext4_ext_path *path = orig_path ? *orig_path : NULL; |
| short int depth, i, ppos = 0; |
| int ret; |
| |
| eh = ext_inode_hdr(inode); |
| depth = ext_depth(inode); |
| if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) { |
| EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d", |
| depth); |
| ret = -EFSCORRUPTED; |
| goto err; |
| } |
| |
| if (path) { |
| ext4_ext_drop_refs(path); |
| if (depth > path[0].p_maxdepth) { |
| kfree(path); |
| *orig_path = path = NULL; |
| } |
| } |
| if (!path) { |
| /* account possible depth increase */ |
| path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2), |
| GFP_NOFS); |
| if (unlikely(!path)) |
| return ERR_PTR(-ENOMEM); |
| path[0].p_maxdepth = depth + 1; |
| } |
| path[0].p_hdr = eh; |
| path[0].p_bh = NULL; |
| |
| i = depth; |
| /* walk through the tree */ |
| while (i) { |
| ext_debug("depth %d: num %d, max %d\n", |
| ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); |
| |
| ext4_ext_binsearch_idx(inode, path + ppos, block); |
| path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx); |
| path[ppos].p_depth = i; |
| path[ppos].p_ext = NULL; |
| |
| bh = read_extent_tree_block(inode, path[ppos].p_block, --i, |
| flags); |
| if (IS_ERR(bh)) { |
| ret = PTR_ERR(bh); |
| goto err; |
| } |
| |
| eh = ext_block_hdr(bh); |
| ppos++; |
| path[ppos].p_bh = bh; |
| path[ppos].p_hdr = eh; |
| } |
| |
| path[ppos].p_depth = i; |
| path[ppos].p_ext = NULL; |
| path[ppos].p_idx = NULL; |
| |
| /* find extent */ |
| ext4_ext_binsearch(inode, path + ppos, block); |
| /* if not an empty leaf */ |
| if (path[ppos].p_ext) |
| path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext); |
| |
| ext4_ext_show_path(inode, path); |
| |
| return path; |
| |
| err: |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| if (orig_path) |
| *orig_path = NULL; |
| return ERR_PTR(ret); |
| } |
| |
| /* |
| * ext4_ext_insert_index: |
| * insert new index [@logical;@ptr] into the block at @curp; |
| * check where to insert: before @curp or after @curp |
| */ |
| static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *curp, |
| int logical, ext4_fsblk_t ptr) |
| { |
| struct ext4_extent_idx *ix; |
| int len, err; |
| |
| err = ext4_ext_get_access(handle, inode, curp); |
| if (err) |
| return err; |
| |
| if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) { |
| EXT4_ERROR_INODE(inode, |
| "logical %d == ei_block %d!", |
| logical, le32_to_cpu(curp->p_idx->ei_block)); |
| return -EFSCORRUPTED; |
| } |
| |
| if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries) |
| >= le16_to_cpu(curp->p_hdr->eh_max))) { |
| EXT4_ERROR_INODE(inode, |
| "eh_entries %d >= eh_max %d!", |
| le16_to_cpu(curp->p_hdr->eh_entries), |
| le16_to_cpu(curp->p_hdr->eh_max)); |
| return -EFSCORRUPTED; |
| } |
| |
| if (logical > le32_to_cpu(curp->p_idx->ei_block)) { |
| /* insert after */ |
| ext_debug("insert new index %d after: %llu\n", logical, ptr); |
| ix = curp->p_idx + 1; |
| } else { |
| /* insert before */ |
| ext_debug("insert new index %d before: %llu\n", logical, ptr); |
| ix = curp->p_idx; |
| } |
| |
| len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1; |
| BUG_ON(len < 0); |
| if (len > 0) { |
| ext_debug("insert new index %d: " |
| "move %d indices from 0x%p to 0x%p\n", |
| logical, len, ix, ix + 1); |
| memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx)); |
| } |
| |
| if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) { |
| EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!"); |
| return -EFSCORRUPTED; |
| } |
| |
| ix->ei_block = cpu_to_le32(logical); |
| ext4_idx_store_pblock(ix, ptr); |
| le16_add_cpu(&curp->p_hdr->eh_entries, 1); |
| |
| if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) { |
| EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!"); |
| return -EFSCORRUPTED; |
| } |
| |
| err = ext4_ext_dirty(handle, inode, curp); |
| ext4_std_error(inode->i_sb, err); |
| |
| return err; |
| } |
| |
| /* |
| * ext4_ext_split: |
| * inserts new subtree into the path, using free index entry |
| * at depth @at: |
| * - allocates all needed blocks (new leaf and all intermediate index blocks) |
| * - makes decision where to split |
| * - moves remaining extents and index entries (right to the split point) |
| * into the newly allocated blocks |
| * - initializes subtree |
| */ |
| static int ext4_ext_split(handle_t *handle, struct inode *inode, |
| unsigned int flags, |
| struct ext4_ext_path *path, |
| struct ext4_extent *newext, int at) |
| { |
| struct buffer_head *bh = NULL; |
| int depth = ext_depth(inode); |
| struct ext4_extent_header *neh; |
| struct ext4_extent_idx *fidx; |
| int i = at, k, m, a; |
| ext4_fsblk_t newblock, oldblock; |
| __le32 border; |
| ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ |
| int err = 0; |
| size_t ext_size = 0; |
| |
| /* make decision: where to split? */ |
| /* FIXME: now decision is simplest: at current extent */ |
| |
| /* if current leaf will be split, then we should use |
| * border from split point */ |
| if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) { |
| EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!"); |
| return -EFSCORRUPTED; |
| } |
| if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { |
| border = path[depth].p_ext[1].ee_block; |
| ext_debug("leaf will be split." |
| " next leaf starts at %d\n", |
| le32_to_cpu(border)); |
| } else { |
| border = newext->ee_block; |
| ext_debug("leaf will be added." |
| " next leaf starts at %d\n", |
| le32_to_cpu(border)); |
| } |
| |
| /* |
| * If error occurs, then we break processing |
| * and mark filesystem read-only. index won't |
| * be inserted and tree will be in consistent |
| * state. Next mount will repair buffers too. |
| */ |
| |
| /* |
| * Get array to track all allocated blocks. |
| * We need this to handle errors and free blocks |
| * upon them. |
| */ |
| ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); |
| if (!ablocks) |
| return -ENOMEM; |
| |
| /* allocate all needed blocks */ |
| ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); |
| for (a = 0; a < depth - at; a++) { |
| newblock = ext4_ext_new_meta_block(handle, inode, path, |
| newext, &err, flags); |
| if (newblock == 0) |
| goto cleanup; |
| ablocks[a] = newblock; |
| } |
| |
| /* initialize new leaf */ |
| newblock = ablocks[--a]; |
| if (unlikely(newblock == 0)) { |
| EXT4_ERROR_INODE(inode, "newblock == 0!"); |
| err = -EFSCORRUPTED; |
| goto cleanup; |
| } |
| bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS); |
| if (unlikely(!bh)) { |
| err = -ENOMEM; |
| goto cleanup; |
| } |
| lock_buffer(bh); |
| |
| err = ext4_journal_get_create_access(handle, bh); |
| if (err) |
| goto cleanup; |
| |
| neh = ext_block_hdr(bh); |
| neh->eh_entries = 0; |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); |
| neh->eh_magic = EXT4_EXT_MAGIC; |
| neh->eh_depth = 0; |
| |
| /* move remainder of path[depth] to the new leaf */ |
| if (unlikely(path[depth].p_hdr->eh_entries != |
| path[depth].p_hdr->eh_max)) { |
| EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!", |
| path[depth].p_hdr->eh_entries, |
| path[depth].p_hdr->eh_max); |
| err = -EFSCORRUPTED; |
| goto cleanup; |
| } |
| /* start copy from next extent */ |
| m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++; |
| ext4_ext_show_move(inode, path, newblock, depth); |
| if (m) { |
| struct ext4_extent *ex; |
| ex = EXT_FIRST_EXTENT(neh); |
| memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m); |
| le16_add_cpu(&neh->eh_entries, m); |
| } |
| |
| /* zero out unused area in the extent block */ |
| ext_size = sizeof(struct ext4_extent_header) + |
| sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries); |
| memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size); |
| ext4_extent_block_csum_set(inode, neh); |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| |
| err = ext4_handle_dirty_metadata(handle, inode, bh); |
| if (err) |
| goto cleanup; |
| brelse(bh); |
| bh = NULL; |
| |
| /* correct old leaf */ |
| if (m) { |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto cleanup; |
| le16_add_cpu(&path[depth].p_hdr->eh_entries, -m); |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| if (err) |
| goto cleanup; |
| |
| } |
| |
| /* create intermediate indexes */ |
| k = depth - at - 1; |
| if (unlikely(k < 0)) { |
| EXT4_ERROR_INODE(inode, "k %d < 0!", k); |
| err = -EFSCORRUPTED; |
| goto cleanup; |
| } |
| if (k) |
| ext_debug("create %d intermediate indices\n", k); |
| /* insert new index into current index block */ |
| /* current depth stored in i var */ |
| i = depth - 1; |
| while (k--) { |
| oldblock = newblock; |
| newblock = ablocks[--a]; |
| bh = sb_getblk(inode->i_sb, newblock); |
| if (unlikely(!bh)) { |
| err = -ENOMEM; |
| goto cleanup; |
| } |
| lock_buffer(bh); |
| |
| err = ext4_journal_get_create_access(handle, bh); |
| if (err) |
| goto cleanup; |
| |
| neh = ext_block_hdr(bh); |
| neh->eh_entries = cpu_to_le16(1); |
| neh->eh_magic = EXT4_EXT_MAGIC; |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); |
| neh->eh_depth = cpu_to_le16(depth - i); |
| fidx = EXT_FIRST_INDEX(neh); |
| fidx->ei_block = border; |
| ext4_idx_store_pblock(fidx, oldblock); |
| |
| ext_debug("int.index at %d (block %llu): %u -> %llu\n", |
| i, newblock, le32_to_cpu(border), oldblock); |
| |
| /* move remainder of path[i] to the new index block */ |
| if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) != |
| EXT_LAST_INDEX(path[i].p_hdr))) { |
| EXT4_ERROR_INODE(inode, |
| "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!", |
| le32_to_cpu(path[i].p_ext->ee_block)); |
| err = -EFSCORRUPTED; |
| goto cleanup; |
| } |
| /* start copy indexes */ |
| m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++; |
| ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, |
| EXT_MAX_INDEX(path[i].p_hdr)); |
| ext4_ext_show_move(inode, path, newblock, i); |
| if (m) { |
| memmove(++fidx, path[i].p_idx, |
| sizeof(struct ext4_extent_idx) * m); |
| le16_add_cpu(&neh->eh_entries, m); |
| } |
| /* zero out unused area in the extent block */ |
| ext_size = sizeof(struct ext4_extent_header) + |
| (sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries)); |
| memset(bh->b_data + ext_size, 0, |
| inode->i_sb->s_blocksize - ext_size); |
| ext4_extent_block_csum_set(inode, neh); |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| |
| err = ext4_handle_dirty_metadata(handle, inode, bh); |
| if (err) |
| goto cleanup; |
| brelse(bh); |
| bh = NULL; |
| |
| /* correct old index */ |
| if (m) { |
| err = ext4_ext_get_access(handle, inode, path + i); |
| if (err) |
| goto cleanup; |
| le16_add_cpu(&path[i].p_hdr->eh_entries, -m); |
| err = ext4_ext_dirty(handle, inode, path + i); |
| if (err) |
| goto cleanup; |
| } |
| |
| i--; |
| } |
| |
| /* insert new index */ |
| err = ext4_ext_insert_index(handle, inode, path + at, |
| le32_to_cpu(border), newblock); |
| |
| cleanup: |
| if (bh) { |
| if (buffer_locked(bh)) |
| unlock_buffer(bh); |
| brelse(bh); |
| } |
| |
| if (err) { |
| /* free all allocated blocks in error case */ |
| for (i = 0; i < depth; i++) { |
| if (!ablocks[i]) |
| continue; |
| ext4_free_blocks(handle, inode, NULL, ablocks[i], 1, |
| EXT4_FREE_BLOCKS_METADATA); |
| } |
| } |
| kfree(ablocks); |
| |
| return err; |
| } |
| |
| /* |
| * ext4_ext_grow_indepth: |
| * implements tree growing procedure: |
| * - allocates new block |
| * - moves top-level data (index block or leaf) into the new block |
| * - initializes new top-level, creating index that points to the |
| * just created block |
| */ |
| static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, |
| unsigned int flags) |
| { |
| struct ext4_extent_header *neh; |
| struct buffer_head *bh; |
| ext4_fsblk_t newblock, goal = 0; |
| struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es; |
| int err = 0; |
| size_t ext_size = 0; |
| |
| /* Try to prepend new index to old one */ |
| if (ext_depth(inode)) |
| goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode))); |
| if (goal > le32_to_cpu(es->s_first_data_block)) { |
| flags |= EXT4_MB_HINT_TRY_GOAL; |
| goal--; |
| } else |
| goal = ext4_inode_to_goal_block(inode); |
| newblock = ext4_new_meta_blocks(handle, inode, goal, flags, |
| NULL, &err); |
| if (newblock == 0) |
| return err; |
| |
| bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS); |
| if (unlikely(!bh)) |
| return -ENOMEM; |
| lock_buffer(bh); |
| |
| err = ext4_journal_get_create_access(handle, bh); |
| if (err) { |
| unlock_buffer(bh); |
| goto out; |
| } |
| |
| ext_size = sizeof(EXT4_I(inode)->i_data); |
| /* move top-level index/leaf into new block */ |
| memmove(bh->b_data, EXT4_I(inode)->i_data, ext_size); |
| /* zero out unused area in the extent block */ |
| memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size); |
| |
| /* set size of new block */ |
| neh = ext_block_hdr(bh); |
| /* old root could have indexes or leaves |
| * so calculate e_max right way */ |
| if (ext_depth(inode)) |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); |
| else |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); |
| neh->eh_magic = EXT4_EXT_MAGIC; |
| ext4_extent_block_csum_set(inode, neh); |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| |
| err = ext4_handle_dirty_metadata(handle, inode, bh); |
| if (err) |
| goto out; |
| |
| /* Update top-level index: num,max,pointer */ |
| neh = ext_inode_hdr(inode); |
| neh->eh_entries = cpu_to_le16(1); |
| ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock); |
| if (neh->eh_depth == 0) { |
| /* Root extent block becomes index block */ |
| neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0)); |
| EXT_FIRST_INDEX(neh)->ei_block = |
| EXT_FIRST_EXTENT(neh)->ee_block; |
| } |
| ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", |
| le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), |
| le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), |
| ext4_idx_pblock(EXT_FIRST_INDEX(neh))); |
| |
| le16_add_cpu(&neh->eh_depth, 1); |
| ext4_mark_inode_dirty(handle, inode); |
| out: |
| brelse(bh); |
| |
| return err; |
| } |
| |
| /* |
| * ext4_ext_create_new_leaf: |
| * finds empty index and adds new leaf. |
| * if no free index is found, then it requests in-depth growing. |
| */ |
| static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, |
| unsigned int mb_flags, |
| unsigned int gb_flags, |
| struct ext4_ext_path **ppath, |
| struct ext4_extent *newext) |
| { |
| struct ext4_ext_path *path = *ppath; |
| struct ext4_ext_path *curp; |
| int depth, i, err = 0; |
| |
| repeat: |
| i = depth = ext_depth(inode); |
| |
| /* walk up to the tree and look for free index entry */ |
| curp = path + depth; |
| while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { |
| i--; |
| curp--; |
| } |
| |
| /* we use already allocated block for index block, |
| * so subsequent data blocks should be contiguous */ |
| if (EXT_HAS_FREE_INDEX(curp)) { |
| /* if we found index with free entry, then use that |
| * entry: create all needed subtree and add new leaf */ |
| err = ext4_ext_split(handle, inode, mb_flags, path, newext, i); |
| if (err) |
| goto out; |
| |
| /* refill path */ |
| path = ext4_find_extent(inode, |
| (ext4_lblk_t)le32_to_cpu(newext->ee_block), |
| ppath, gb_flags); |
| if (IS_ERR(path)) |
| err = PTR_ERR(path); |
| } else { |
| /* tree is full, time to grow in depth */ |
| err = ext4_ext_grow_indepth(handle, inode, mb_flags); |
| if (err) |
| goto out; |
| |
| /* refill path */ |
| path = ext4_find_extent(inode, |
| (ext4_lblk_t)le32_to_cpu(newext->ee_block), |
| ppath, gb_flags); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| goto out; |
| } |
| |
| /* |
| * only first (depth 0 -> 1) produces free space; |
| * in all other cases we have to split the grown tree |
| */ |
| depth = ext_depth(inode); |
| if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { |
| /* now we need to split */ |
| goto repeat; |
| } |
| } |
| |
| out: |
| return err; |
| } |
| |
| /* |
| * search the closest allocated block to the left for *logical |
| * and returns it at @logical + it's physical address at @phys |
| * if *logical is the smallest allocated block, the function |
| * returns 0 at @phys |
| * return value contains 0 (success) or error code |
| */ |
| static int ext4_ext_search_left(struct inode *inode, |
| struct ext4_ext_path *path, |
| ext4_lblk_t *logical, ext4_fsblk_t *phys) |
| { |
| struct ext4_extent_idx *ix; |
| struct ext4_extent *ex; |
| int depth, ee_len; |
| |
| if (unlikely(path == NULL)) { |
| EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); |
| return -EFSCORRUPTED; |
| } |
| depth = path->p_depth; |
| *phys = 0; |
| |
| if (depth == 0 && path->p_ext == NULL) |
| return 0; |
| |
| /* usually extent in the path covers blocks smaller |
| * then *logical, but it can be that extent is the |
| * first one in the file */ |
| |
| ex = path[depth].p_ext; |
| ee_len = ext4_ext_get_actual_len(ex); |
| if (*logical < le32_to_cpu(ex->ee_block)) { |
| if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { |
| EXT4_ERROR_INODE(inode, |
| "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!", |
| *logical, le32_to_cpu(ex->ee_block)); |
| return -EFSCORRUPTED; |
| } |
| while (--depth >= 0) { |
| ix = path[depth].p_idx; |
| if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { |
| EXT4_ERROR_INODE(inode, |
| "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!", |
| ix != NULL ? le32_to_cpu(ix->ei_block) : 0, |
| EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ? |
| le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0, |
| depth); |
| return -EFSCORRUPTED; |
| } |
| } |
| return 0; |
| } |
| |
| if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { |
| EXT4_ERROR_INODE(inode, |
| "logical %d < ee_block %d + ee_len %d!", |
| *logical, le32_to_cpu(ex->ee_block), ee_len); |
| return -EFSCORRUPTED; |
| } |
| |
| *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; |
| *phys = ext4_ext_pblock(ex) + ee_len - 1; |
| return 0; |
| } |
| |
| /* |
| * search the closest allocated block to the right for *logical |
| * and returns it at @logical + it's physical address at @phys |
| * if *logical is the largest allocated block, the function |
| * returns 0 at @phys |
| * return value contains 0 (success) or error code |
| */ |
| static int ext4_ext_search_right(struct inode *inode, |
| struct ext4_ext_path *path, |
| ext4_lblk_t *logical, ext4_fsblk_t *phys, |
| struct ext4_extent **ret_ex) |
| { |
| struct buffer_head *bh = NULL; |
| struct ext4_extent_header *eh; |
| struct ext4_extent_idx *ix; |
| struct ext4_extent *ex; |
| ext4_fsblk_t block; |
| int depth; /* Note, NOT eh_depth; depth from top of tree */ |
| int ee_len; |
| |
| if (unlikely(path == NULL)) { |
| EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); |
| return -EFSCORRUPTED; |
| } |
| depth = path->p_depth; |
| *phys = 0; |
| |
| if (depth == 0 && path->p_ext == NULL) |
| return 0; |
| |
| /* usually extent in the path covers blocks smaller |
| * then *logical, but it can be that extent is the |
| * first one in the file */ |
| |
| ex = path[depth].p_ext; |
| ee_len = ext4_ext_get_actual_len(ex); |
| if (*logical < le32_to_cpu(ex->ee_block)) { |
| if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { |
| EXT4_ERROR_INODE(inode, |
| "first_extent(path[%d].p_hdr) != ex", |
| depth); |
| return -EFSCORRUPTED; |
| } |
| while (--depth >= 0) { |
| ix = path[depth].p_idx; |
| if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { |
| EXT4_ERROR_INODE(inode, |
| "ix != EXT_FIRST_INDEX *logical %d!", |
| *logical); |
| return -EFSCORRUPTED; |
| } |
| } |
| goto found_extent; |
| } |
| |
| if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { |
| EXT4_ERROR_INODE(inode, |
| "logical %d < ee_block %d + ee_len %d!", |
| *logical, le32_to_cpu(ex->ee_block), ee_len); |
| return -EFSCORRUPTED; |
| } |
| |
| if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { |
| /* next allocated block in this leaf */ |
| ex++; |
| goto found_extent; |
| } |
| |
| /* go up and search for index to the right */ |
| while (--depth >= 0) { |
| ix = path[depth].p_idx; |
| if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) |
| goto got_index; |
| } |
| |
| /* we've gone up to the root and found no index to the right */ |
| return 0; |
| |
| got_index: |
| /* we've found index to the right, let's |
| * follow it and find the closest allocated |
| * block to the right */ |
| ix++; |
| block = ext4_idx_pblock(ix); |
| while (++depth < path->p_depth) { |
| /* subtract from p_depth to get proper eh_depth */ |
| bh = read_extent_tree_block(inode, block, |
| path->p_depth - depth, 0); |
| if (IS_ERR(bh)) |
| return PTR_ERR(bh); |
| eh = ext_block_hdr(bh); |
| ix = EXT_FIRST_INDEX(eh); |
| block = ext4_idx_pblock(ix); |
| put_bh(bh); |
| } |
| |
| bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0); |
| if (IS_ERR(bh)) |
| return PTR_ERR(bh); |
| eh = ext_block_hdr(bh); |
| ex = EXT_FIRST_EXTENT(eh); |
| found_extent: |
| *logical = le32_to_cpu(ex->ee_block); |
| *phys = ext4_ext_pblock(ex); |
| *ret_ex = ex; |
| if (bh) |
| put_bh(bh); |
| return 0; |
| } |
| |
| /* |
| * ext4_ext_next_allocated_block: |
| * returns allocated block in subsequent extent or EXT_MAX_BLOCKS. |
| * NOTE: it considers block number from index entry as |
| * allocated block. Thus, index entries have to be consistent |
| * with leaves. |
| */ |
| ext4_lblk_t |
| ext4_ext_next_allocated_block(struct ext4_ext_path *path) |
| { |
| int depth; |
| |
| BUG_ON(path == NULL); |
| depth = path->p_depth; |
| |
| if (depth == 0 && path->p_ext == NULL) |
| return EXT_MAX_BLOCKS; |
| |
| while (depth >= 0) { |
| if (depth == path->p_depth) { |
| /* leaf */ |
| if (path[depth].p_ext && |
| path[depth].p_ext != |
| EXT_LAST_EXTENT(path[depth].p_hdr)) |
| return le32_to_cpu(path[depth].p_ext[1].ee_block); |
| } else { |
| /* index */ |
| if (path[depth].p_idx != |
| EXT_LAST_INDEX(path[depth].p_hdr)) |
| return le32_to_cpu(path[depth].p_idx[1].ei_block); |
| } |
| depth--; |
| } |
| |
| return EXT_MAX_BLOCKS; |
| } |
| |
| /* |
| * ext4_ext_next_leaf_block: |
| * returns first allocated block from next leaf or EXT_MAX_BLOCKS |
| */ |
| static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path) |
| { |
| int depth; |
| |
| BUG_ON(path == NULL); |
| depth = path->p_depth; |
| |
| /* zero-tree has no leaf blocks at all */ |
| if (depth == 0) |
| return EXT_MAX_BLOCKS; |
| |
| /* go to index block */ |
| depth--; |
| |
| while (depth >= 0) { |
| if (path[depth].p_idx != |
| EXT_LAST_INDEX(path[depth].p_hdr)) |
| return (ext4_lblk_t) |
| le32_to_cpu(path[depth].p_idx[1].ei_block); |
| depth--; |
| } |
| |
| return EXT_MAX_BLOCKS; |
| } |
| |
| /* |
| * ext4_ext_correct_indexes: |
| * if leaf gets modified and modified extent is first in the leaf, |
| * then we have to correct all indexes above. |
| * TODO: do we need to correct tree in all cases? |
| */ |
| static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| struct ext4_extent_header *eh; |
| int depth = ext_depth(inode); |
| struct ext4_extent *ex; |
| __le32 border; |
| int k, err = 0; |
| |
| eh = path[depth].p_hdr; |
| ex = path[depth].p_ext; |
| |
| if (unlikely(ex == NULL || eh == NULL)) { |
| EXT4_ERROR_INODE(inode, |
| "ex %p == NULL or eh %p == NULL", ex, eh); |
| return -EFSCORRUPTED; |
| } |
| |
| if (depth == 0) { |
| /* there is no tree at all */ |
| return 0; |
| } |
| |
| if (ex != EXT_FIRST_EXTENT(eh)) { |
| /* we correct tree if first leaf got modified only */ |
| return 0; |
| } |
| |
| /* |
| * TODO: we need correction if border is smaller than current one |
| */ |
| k = depth - 1; |
| border = path[depth].p_ext->ee_block; |
| err = ext4_ext_get_access(handle, inode, path + k); |
| if (err) |
| return err; |
| path[k].p_idx->ei_block = border; |
| err = ext4_ext_dirty(handle, inode, path + k); |
| if (err) |
| return err; |
| |
| while (k--) { |
| /* change all left-side indexes */ |
| if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) |
| break; |
| err = ext4_ext_get_access(handle, inode, path + k); |
| if (err) |
| break; |
| path[k].p_idx->ei_block = border; |
| err = ext4_ext_dirty(handle, inode, path + k); |
| if (err) |
| break; |
| } |
| |
| return err; |
| } |
| |
| int |
| ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, |
| struct ext4_extent *ex2) |
| { |
| unsigned short ext1_ee_len, ext2_ee_len; |
| |
| if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2)) |
| return 0; |
| |
| ext1_ee_len = ext4_ext_get_actual_len(ex1); |
| ext2_ee_len = ext4_ext_get_actual_len(ex2); |
| |
| if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != |
| le32_to_cpu(ex2->ee_block)) |
| return 0; |
| |
| /* |
| * To allow future support for preallocated extents to be added |
| * as an RO_COMPAT feature, refuse to merge to extents if |
| * this can result in the top bit of ee_len being set. |
| */ |
| if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN) |
| return 0; |
| /* |
| * The check for IO to unwritten extent is somewhat racy as we |
| * increment i_unwritten / set EXT4_STATE_DIO_UNWRITTEN only after |
| * dropping i_data_sem. But reserved blocks should save us in that |
| * case. |
| */ |
| if (ext4_ext_is_unwritten(ex1) && |
| (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) || |
| atomic_read(&EXT4_I(inode)->i_unwritten) || |
| (ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN))) |
| return 0; |
| #ifdef AGGRESSIVE_TEST |
| if (ext1_ee_len >= 4) |
| return 0; |
| #endif |
| |
| if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2)) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * This function tries to merge the "ex" extent to the next extent in the tree. |
| * It always tries to merge towards right. If you want to merge towards |
| * left, pass "ex - 1" as argument instead of "ex". |
| * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns |
| * 1 if they got merged. |
| */ |
| static int ext4_ext_try_to_merge_right(struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *ex) |
| { |
| struct ext4_extent_header *eh; |
| unsigned int depth, len; |
| int merge_done = 0, unwritten; |
| |
| depth = ext_depth(inode); |
| BUG_ON(path[depth].p_hdr == NULL); |
| eh = path[depth].p_hdr; |
| |
| while (ex < EXT_LAST_EXTENT(eh)) { |
| if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) |
| break; |
| /* merge with next extent! */ |
| unwritten = ext4_ext_is_unwritten(ex); |
| ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) |
| + ext4_ext_get_actual_len(ex + 1)); |
| if (unwritten) |
| ext4_ext_mark_unwritten(ex); |
| |
| if (ex + 1 < EXT_LAST_EXTENT(eh)) { |
| len = (EXT_LAST_EXTENT(eh) - ex - 1) |
| * sizeof(struct ext4_extent); |
| memmove(ex + 1, ex + 2, len); |
| } |
| le16_add_cpu(&eh->eh_entries, -1); |
| merge_done = 1; |
| WARN_ON(eh->eh_entries == 0); |
| if (!eh->eh_entries) |
| EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!"); |
| } |
| |
| return merge_done; |
| } |
| |
| /* |
| * This function does a very simple check to see if we can collapse |
| * an extent tree with a single extent tree leaf block into the inode. |
| */ |
| static void ext4_ext_try_to_merge_up(handle_t *handle, |
| struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| size_t s; |
| unsigned max_root = ext4_ext_space_root(inode, 0); |
| ext4_fsblk_t blk; |
| |
| if ((path[0].p_depth != 1) || |
| (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) || |
| (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root)) |
| return; |
| |
| /* |
| * We need to modify the block allocation bitmap and the block |
| * group descriptor to release the extent tree block. If we |
| * can't get the journal credits, give up. |
| */ |
| if (ext4_journal_extend(handle, 2)) |
| return; |
| |
| /* |
| * Copy the extent data up to the inode |
| */ |
| blk = ext4_idx_pblock(path[0].p_idx); |
| s = le16_to_cpu(path[1].p_hdr->eh_entries) * |
| sizeof(struct ext4_extent_idx); |
| s += sizeof(struct ext4_extent_header); |
| |
| path[1].p_maxdepth = path[0].p_maxdepth; |
| memcpy(path[0].p_hdr, path[1].p_hdr, s); |
| path[0].p_depth = 0; |
| path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) + |
| (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr)); |
| path[0].p_hdr->eh_max = cpu_to_le16(max_root); |
| |
| brelse(path[1].p_bh); |
| ext4_free_blocks(handle, inode, NULL, blk, 1, |
| EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); |
| } |
| |
| /* |
| * This function tries to merge the @ex extent to neighbours in the tree. |
| * return 1 if merge left else 0. |
| */ |
| static void ext4_ext_try_to_merge(handle_t *handle, |
| struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *ex) { |
| struct ext4_extent_header *eh; |
| unsigned int depth; |
| int merge_done = 0; |
| |
| depth = ext_depth(inode); |
| BUG_ON(path[depth].p_hdr == NULL); |
| eh = path[depth].p_hdr; |
| |
| if (ex > EXT_FIRST_EXTENT(eh)) |
| merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1); |
| |
| if (!merge_done) |
| (void) ext4_ext_try_to_merge_right(inode, path, ex); |
| |
| ext4_ext_try_to_merge_up(handle, inode, path); |
| } |
| |
| /* |
| * check if a portion of the "newext" extent overlaps with an |
| * existing extent. |
| * |
| * If there is an overlap discovered, it updates the length of the newext |
| * such that there will be no overlap, and then returns 1. |
| * If there is no overlap found, it returns 0. |
| */ |
| static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi, |
| struct inode *inode, |
| struct ext4_extent *newext, |
| struct ext4_ext_path *path) |
| { |
| ext4_lblk_t b1, b2; |
| unsigned int depth, len1; |
| unsigned int ret = 0; |
| |
| b1 = le32_to_cpu(newext->ee_block); |
| len1 = ext4_ext_get_actual_len(newext); |
| depth = ext_depth(inode); |
| if (!path[depth].p_ext) |
| goto out; |
| b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block)); |
| |
| /* |
| * get the next allocated block if the extent in the path |
| * is before the requested block(s) |
| */ |
| if (b2 < b1) { |
| b2 = ext4_ext_next_allocated_block(path); |
| if (b2 == EXT_MAX_BLOCKS) |
| goto out; |
| b2 = EXT4_LBLK_CMASK(sbi, b2); |
| } |
| |
| /* check for wrap through zero on extent logical start block*/ |
| if (b1 + len1 < b1) { |
| len1 = EXT_MAX_BLOCKS - b1; |
| newext->ee_len = cpu_to_le16(len1); |
| ret = 1; |
| } |
| |
| /* check for overlap */ |
| if (b1 + len1 > b2) { |
| newext->ee_len = cpu_to_le16(b2 - b1); |
| ret = 1; |
| } |
| out: |
| return ret; |
| } |
| |
| /* |
| * ext4_ext_insert_extent: |
| * tries to merge requsted extent into the existing extent or |
| * inserts requested extent as new one into the tree, |
| * creating new leaf in the no-space case. |
| */ |
| int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path **ppath, |
| struct ext4_extent *newext, int gb_flags) |
| { |
| struct ext4_ext_path *path = *ppath; |
| struct ext4_extent_header *eh; |
| struct ext4_extent *ex, *fex; |
| struct ext4_extent *nearex; /* nearest extent */ |
| struct ext4_ext_path *npath = NULL; |
| int depth, len, err; |
| ext4_lblk_t next; |
| int mb_flags = 0, unwritten; |
| |
| if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) |
| mb_flags |= EXT4_MB_DELALLOC_RESERVED; |
| if (unlikely(ext4_ext_get_actual_len(newext) == 0)) { |
| EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0"); |
| return -EFSCORRUPTED; |
| } |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| eh = path[depth].p_hdr; |
| if (unlikely(path[depth].p_hdr == NULL)) { |
| EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); |
| return -EFSCORRUPTED; |
| } |
| |
| /* try to insert block into found extent and return */ |
| if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) { |
| |
| /* |
| * Try to see whether we should rather test the extent on |
| * right from ex, or from the left of ex. This is because |
| * ext4_find_extent() can return either extent on the |
| * left, or on the right from the searched position. This |
| * will make merging more effective. |
| */ |
| if (ex < EXT_LAST_EXTENT(eh) && |
| (le32_to_cpu(ex->ee_block) + |
| ext4_ext_get_actual_len(ex) < |
| le32_to_cpu(newext->ee_block))) { |
| ex += 1; |
| goto prepend; |
| } else if ((ex > EXT_FIRST_EXTENT(eh)) && |
| (le32_to_cpu(newext->ee_block) + |
| ext4_ext_get_actual_len(newext) < |
| le32_to_cpu(ex->ee_block))) |
| ex -= 1; |
| |
| /* Try to append newex to the ex */ |
| if (ext4_can_extents_be_merged(inode, ex, newext)) { |
| ext_debug("append [%d]%d block to %u:[%d]%d" |
| "(from %llu)\n", |
| ext4_ext_is_unwritten(newext), |
| ext4_ext_get_actual_len(newext), |
| le32_to_cpu(ex->ee_block), |
| ext4_ext_is_unwritten(ex), |
| ext4_ext_get_actual_len(ex), |
| ext4_ext_pblock(ex)); |
| err = ext4_ext_get_access(handle, inode, |
| path + depth); |
| if (err) |
| return err; |
| unwritten = ext4_ext_is_unwritten(ex); |
| ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) |
| + ext4_ext_get_actual_len(newext)); |
| if (unwritten) |
| ext4_ext_mark_unwritten(ex); |
| eh = path[depth].p_hdr; |
| nearex = ex; |
| goto merge; |
| } |
| |
| prepend: |
| /* Try to prepend newex to the ex */ |
| if (ext4_can_extents_be_merged(inode, newext, ex)) { |
| ext_debug("prepend %u[%d]%d block to %u:[%d]%d" |
| "(from %llu)\n", |
| le32_to_cpu(newext->ee_block), |
| ext4_ext_is_unwritten(newext), |
| ext4_ext_get_actual_len(newext), |
| le32_to_cpu(ex->ee_block), |
| ext4_ext_is_unwritten(ex), |
| ext4_ext_get_actual_len(ex), |
| ext4_ext_pblock(ex)); |
| err = ext4_ext_get_access(handle, inode, |
| path + depth); |
| if (err) |
| return err; |
| |
| unwritten = ext4_ext_is_unwritten(ex); |
| ex->ee_block = newext->ee_block; |
| ext4_ext_store_pblock(ex, ext4_ext_pblock(newext)); |
| ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) |
| + ext4_ext_get_actual_len(newext)); |
| if (unwritten) |
| ext4_ext_mark_unwritten(ex); |
| eh = path[depth].p_hdr; |
| nearex = ex; |
| goto merge; |
| } |
| } |
| |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) |
| goto has_space; |
| |
| /* probably next leaf has space for us? */ |
| fex = EXT_LAST_EXTENT(eh); |
| next = EXT_MAX_BLOCKS; |
| if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)) |
| next = ext4_ext_next_leaf_block(path); |
| if (next != EXT_MAX_BLOCKS) { |
| ext_debug("next leaf block - %u\n", next); |
| BUG_ON(npath != NULL); |
| npath = ext4_find_extent(inode, next, NULL, 0); |
| if (IS_ERR(npath)) |
| return PTR_ERR(npath); |
| BUG_ON(npath->p_depth != path->p_depth); |
| eh = npath[depth].p_hdr; |
| if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { |
| ext_debug("next leaf isn't full(%d)\n", |
| le16_to_cpu(eh->eh_entries)); |
| path = npath; |
| goto has_space; |
| } |
| ext_debug("next leaf has no free space(%d,%d)\n", |
| le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); |
| } |
| |
| /* |
| * There is no free space in the found leaf. |
| * We're gonna add a new leaf in the tree. |
| */ |
| if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL) |
| mb_flags |= EXT4_MB_USE_RESERVED; |
| err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags, |
| ppath, newext); |
| if (err) |
| goto cleanup; |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| |
| has_space: |
| nearex = path[depth].p_ext; |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto cleanup; |
| |
| if (!nearex) { |
| /* there is no extent in this leaf, create first one */ |
| ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n", |
| le32_to_cpu(newext->ee_block), |
| ext4_ext_pblock(newext), |
| ext4_ext_is_unwritten(newext), |
| ext4_ext_get_actual_len(newext)); |
| nearex = EXT_FIRST_EXTENT(eh); |
| } else { |
| if (le32_to_cpu(newext->ee_block) |
| > le32_to_cpu(nearex->ee_block)) { |
| /* Insert after */ |
| ext_debug("insert %u:%llu:[%d]%d before: " |
| "nearest %p\n", |
| le32_to_cpu(newext->ee_block), |
| ext4_ext_pblock(newext), |
| ext4_ext_is_unwritten(newext), |
| ext4_ext_get_actual_len(newext), |
| nearex); |
| nearex++; |
| } else { |
| /* Insert before */ |
| BUG_ON(newext->ee_block == nearex->ee_block); |
| ext_debug("insert %u:%llu:[%d]%d after: " |
| "nearest %p\n", |
| le32_to_cpu(newext->ee_block), |
| ext4_ext_pblock(newext), |
| ext4_ext_is_unwritten(newext), |
| ext4_ext_get_actual_len(newext), |
| nearex); |
| } |
| len = EXT_LAST_EXTENT(eh) - nearex + 1; |
| if (len > 0) { |
| ext_debug("insert %u:%llu:[%d]%d: " |
| "move %d extents from 0x%p to 0x%p\n", |
| le32_to_cpu(newext->ee_block), |
| ext4_ext_pblock(newext), |
| ext4_ext_is_unwritten(newext), |
| ext4_ext_get_actual_len(newext), |
| len, nearex, nearex + 1); |
| memmove(nearex + 1, nearex, |
| len * sizeof(struct ext4_extent)); |
| } |
| } |
| |
| le16_add_cpu(&eh->eh_entries, 1); |
| path[depth].p_ext = nearex; |
| nearex->ee_block = newext->ee_block; |
| ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext)); |
| nearex->ee_len = newext->ee_len; |
| |
| merge: |
| /* try to merge extents */ |
| if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) |
| ext4_ext_try_to_merge(handle, inode, path, nearex); |
| |
| |
| /* time to correct all indexes above */ |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| if (err) |
| goto cleanup; |
| |
| err = ext4_ext_dirty(handle, inode, path + path->p_depth); |
| |
| cleanup: |
| ext4_ext_drop_refs(npath); |
| kfree(npath); |
| return err; |
| } |
| |
| static int ext4_fill_fiemap_extents(struct inode *inode, |
| ext4_lblk_t block, ext4_lblk_t num, |
| struct fiemap_extent_info *fieinfo) |
| { |
| struct ext4_ext_path *path = NULL; |
| struct ext4_extent *ex; |
| struct extent_status es; |
| ext4_lblk_t next, next_del, start = 0, end = 0; |
| ext4_lblk_t last = block + num; |
| int exists, depth = 0, err = 0; |
| unsigned int flags = 0; |
| unsigned char blksize_bits = inode->i_sb->s_blocksize_bits; |
| |
| while (block < last && block != EXT_MAX_BLOCKS) { |
| num = last - block; |
| /* find extent for this block */ |
| down_read(&EXT4_I(inode)->i_data_sem); |
| |
| path = ext4_find_extent(inode, block, &path, 0); |
| if (IS_ERR(path)) { |
| up_read(&EXT4_I(inode)->i_data_sem); |
| err = PTR_ERR(path); |
| path = NULL; |
| break; |
| } |
| |
| depth = ext_depth(inode); |
| if (unlikely(path[depth].p_hdr == NULL)) { |
| up_read(&EXT4_I(inode)->i_data_sem); |
| EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); |
| err = -EFSCORRUPTED; |
| break; |
| } |
| ex = path[depth].p_ext; |
| next = ext4_ext_next_allocated_block(path); |
| |
| flags = 0; |
| exists = 0; |
| if (!ex) { |
| /* there is no extent yet, so try to allocate |
| * all requested space */ |
| start = block; |
| end = block + num; |
| } else if (le32_to_cpu(ex->ee_block) > block) { |
| /* need to allocate space before found extent */ |
| start = block; |
| end = le32_to_cpu(ex->ee_block); |
| if (block + num < end) |
| end = block + num; |
| } else if (block >= le32_to_cpu(ex->ee_block) |
| + ext4_ext_get_actual_len(ex)) { |
| /* need to allocate space after found extent */ |
| start = block; |
| end = block + num; |
| if (end >= next) |
| end = next; |
| } else if (block >= le32_to_cpu(ex->ee_block)) { |
| /* |
| * some part of requested space is covered |
| * by found extent |
| */ |
| start = block; |
| end = le32_to_cpu(ex->ee_block) |
| + ext4_ext_get_actual_len(ex); |
| if (block + num < end) |
| end = block + num; |
| exists = 1; |
| } else { |
| BUG(); |
| } |
| BUG_ON(end <= start); |
| |
| if (!exists) { |
| es.es_lblk = start; |
| es.es_len = end - start; |
| es.es_pblk = 0; |
| } else { |
| es.es_lblk = le32_to_cpu(ex->ee_block); |
| es.es_len = ext4_ext_get_actual_len(ex); |
| es.es_pblk = ext4_ext_pblock(ex); |
| if (ext4_ext_is_unwritten(ex)) |
| flags |= FIEMAP_EXTENT_UNWRITTEN; |
| } |
| |
| /* |
| * Find delayed extent and update es accordingly. We call |
| * it even in !exists case to find out whether es is the |
| * last existing extent or not. |
| */ |
| next_del = ext4_find_delayed_extent(inode, &es); |
| if (!exists && next_del) { |
| exists = 1; |
| flags |= (FIEMAP_EXTENT_DELALLOC | |
| FIEMAP_EXTENT_UNKNOWN); |
| } |
| up_read(&EXT4_I(inode)->i_data_sem); |
| |
| if (unlikely(es.es_len == 0)) { |
| EXT4_ERROR_INODE(inode, "es.es_len == 0"); |
| err = -EFSCORRUPTED; |
| break; |
| } |
| |
| /* |
| * This is possible iff next == next_del == EXT_MAX_BLOCKS. |
| * we need to check next == EXT_MAX_BLOCKS because it is |
| * possible that an extent is with unwritten and delayed |
| * status due to when an extent is delayed allocated and |
| * is allocated by fallocate status tree will track both of |
| * them in a extent. |
| * |
| * So we could return a unwritten and delayed extent, and |
| * its block is equal to 'next'. |
| */ |
| if (next == next_del && next == EXT_MAX_BLOCKS) { |
| flags |= FIEMAP_EXTENT_LAST; |
| if (unlikely(next_del != EXT_MAX_BLOCKS || |
| next != EXT_MAX_BLOCKS)) { |
| EXT4_ERROR_INODE(inode, |
| "next extent == %u, next " |
| "delalloc extent = %u", |
| next, next_del); |
| err = -EFSCORRUPTED; |
| break; |
| } |
| } |
| |
| if (exists) { |
| err = fiemap_fill_next_extent(fieinfo, |
| (__u64)es.es_lblk << blksize_bits, |
| (__u64)es.es_pblk << blksize_bits, |
| (__u64)es.es_len << blksize_bits, |
| flags); |
| if (err < 0) |
| break; |
| if (err == 1) { |
| err = 0; |
| break; |
| } |
| } |
| |
| block = es.es_lblk + es.es_len; |
| } |
| |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| return err; |
| } |
| |
| /* |
| * ext4_ext_determine_hole - determine hole around given block |
| * @inode: inode we lookup in |
| * @path: path in extent tree to @lblk |
| * @lblk: pointer to logical block around which we want to determine hole |
| * |
| * Determine hole length (and start if easily possible) around given logical |
| * block. We don't try too hard to find the beginning of the hole but @path |
| * actually points to extent before @lblk, we provide it. |
| * |
| * The function returns the length of a hole starting at @lblk. We update @lblk |
| * to the beginning of the hole if we managed to find it. |
| */ |
| static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode, |
| struct ext4_ext_path *path, |
| ext4_lblk_t *lblk) |
| { |
| int depth = ext_depth(inode); |
| struct ext4_extent *ex; |
| ext4_lblk_t len; |
| |
| ex = path[depth].p_ext; |
| if (ex == NULL) { |
| /* there is no extent yet, so gap is [0;-] */ |
| *lblk = 0; |
| len = EXT_MAX_BLOCKS; |
| } else if (*lblk < le32_to_cpu(ex->ee_block)) { |
| len = le32_to_cpu(ex->ee_block) - *lblk; |
| } else if (*lblk >= le32_to_cpu(ex->ee_block) |
| + ext4_ext_get_actual_len(ex)) { |
| ext4_lblk_t next; |
| |
| *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex); |
| next = ext4_ext_next_allocated_block(path); |
| BUG_ON(next == *lblk); |
| len = next - *lblk; |
| } else { |
| BUG(); |
| } |
| return len; |
| } |
| |
| /* |
| * ext4_ext_put_gap_in_cache: |
| * calculate boundaries of the gap that the requested block fits into |
| * and cache this gap |
| */ |
| static void |
| ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start, |
| ext4_lblk_t hole_len) |
| { |
| struct extent_status es; |
| |
| ext4_es_find_delayed_extent_range(inode, hole_start, |
| hole_start + hole_len - 1, &es); |
| if (es.es_len) { |
| /* There's delayed extent containing lblock? */ |
| if (es.es_lblk <= hole_start) |
| return; |
| hole_len = min(es.es_lblk - hole_start, hole_len); |
| } |
| ext_debug(" -> %u:%u\n", hole_start, hole_len); |
| ext4_es_insert_extent(inode, hole_start, hole_len, ~0, |
| EXTENT_STATUS_HOLE); |
| } |
| |
| /* |
| * ext4_ext_rm_idx: |
| * removes index from the index block. |
| */ |
| static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, int depth) |
| { |
| int err; |
| ext4_fsblk_t leaf; |
| |
| /* free index block */ |
| depth--; |
| path = path + depth; |
| leaf = ext4_idx_pblock(path->p_idx); |
| if (unlikely(path->p_hdr->eh_entries == 0)) { |
| EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0"); |
| return -EFSCORRUPTED; |
| } |
| err = ext4_ext_get_access(handle, inode, path); |
| if (err) |
| return err; |
| |
| if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) { |
| int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx; |
| len *= sizeof(struct ext4_extent_idx); |
| memmove(path->p_idx, path->p_idx + 1, len); |
| } |
| |
| le16_add_cpu(&path->p_hdr->eh_entries, -1); |
| err = ext4_ext_dirty(handle, inode, path); |
| if (err) |
| return err; |
| ext_debug("index is empty, remove it, free block %llu\n", leaf); |
| trace_ext4_ext_rm_idx(inode, leaf); |
| |
| ext4_free_blocks(handle, inode, NULL, leaf, 1, |
| EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); |
| |
| while (--depth >= 0) { |
| if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr)) |
| break; |
| path--; |
| err = ext4_ext_get_access(handle, inode, path); |
| if (err) |
| break; |
| path->p_idx->ei_block = (path+1)->p_idx->ei_block; |
| err = ext4_ext_dirty(handle, inode, path); |
| if (err) |
| break; |
| } |
| return err; |
| } |
| |
| /* |
| * ext4_ext_calc_credits_for_single_extent: |
| * This routine returns max. credits that needed to insert an extent |
| * to the extent tree. |
| * When pass the actual path, the caller should calculate credits |
| * under i_data_sem. |
| */ |
| int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks, |
| struct ext4_ext_path *path) |
| { |
| if (path) { |
| int depth = ext_depth(inode); |
| int ret = 0; |
| |
| /* probably there is space in leaf? */ |
| if (le16_to_cpu(path[depth].p_hdr->eh_entries) |
| < le16_to_cpu(path[depth].p_hdr->eh_max)) { |
| |
| /* |
| * There are some space in the leaf tree, no |
| * need to account for leaf block credit |
| * |
| * bitmaps and block group descriptor blocks |
| * and other metadata blocks still need to be |
| * accounted. |
| */ |
| /* 1 bitmap, 1 block group descriptor */ |
| ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb); |
| return ret; |
| } |
| } |
| |
| return ext4_chunk_trans_blocks(inode, nrblocks); |
| } |
| |
| /* |
| * How many index/leaf blocks need to change/allocate to add @extents extents? |
| * |
| * If we add a single extent, then in the worse case, each tree level |
| * index/leaf need to be changed in case of the tree split. |
| * |
| * If more extents are inserted, they could cause the whole tree split more |
| * than once, but this is really rare. |
| */ |
| int ext4_ext_index_trans_blocks(struct inode *inode, int extents) |
| { |
| int index; |
| int depth; |
| |
| /* If we are converting the inline data, only one is needed here. */ |
| if (ext4_has_inline_data(inode)) |
| return 1; |
| |
| depth = ext_depth(inode); |
| |
| if (extents <= 1) |
| index = depth * 2; |
| else |
| index = depth * 3; |
| |
| return index; |
| } |
| |
| static inline int get_default_free_blocks_flags(struct inode *inode) |
| { |
| if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) |
| return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET; |
| else if (ext4_should_journal_data(inode)) |
| return EXT4_FREE_BLOCKS_FORGET; |
| return 0; |
| } |
| |
| static int ext4_remove_blocks(handle_t *handle, struct inode *inode, |
| struct ext4_extent *ex, |
| long long *partial_cluster, |
| ext4_lblk_t from, ext4_lblk_t to) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| unsigned short ee_len = ext4_ext_get_actual_len(ex); |
| ext4_fsblk_t pblk; |
| int flags = get_default_free_blocks_flags(inode); |
| |
| /* |
| * For bigalloc file systems, we never free a partial cluster |
| * at the beginning of the extent. Instead, we make a note |
| * that we tried freeing the cluster, and check to see if we |
| * need to free it on a subsequent call to ext4_remove_blocks, |
| * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space. |
| */ |
| flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER; |
| |
| trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster); |
| /* |
| * If we have a partial cluster, and it's different from the |
| * cluster of the last block, we need to explicitly free the |
| * partial cluster here. |
| */ |
| pblk = ext4_ext_pblock(ex) + ee_len - 1; |
| if (*partial_cluster > 0 && |
| *partial_cluster != (long long) EXT4_B2C(sbi, pblk)) { |
| ext4_free_blocks(handle, inode, NULL, |
| EXT4_C2B(sbi, *partial_cluster), |
| sbi->s_cluster_ratio, flags); |
| *partial_cluster = 0; |
| } |
| |
| #ifdef EXTENTS_STATS |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| spin_lock(&sbi->s_ext_stats_lock); |
| sbi->s_ext_blocks += ee_len; |
| sbi->s_ext_extents++; |
| if (ee_len < sbi->s_ext_min) |
| sbi->s_ext_min = ee_len; |
| if (ee_len > sbi->s_ext_max) |
| sbi->s_ext_max = ee_len; |
| if (ext_depth(inode) > sbi->s_depth_max) |
| sbi->s_depth_max = ext_depth(inode); |
| spin_unlock(&sbi->s_ext_stats_lock); |
| } |
| #endif |
| if (from >= le32_to_cpu(ex->ee_block) |
| && to == le32_to_cpu(ex->ee_block) + ee_len - 1) { |
| /* tail removal */ |
| ext4_lblk_t num; |
| long long first_cluster; |
| |
| num = le32_to_cpu(ex->ee_block) + ee_len - from; |
| pblk = ext4_ext_pblock(ex) + ee_len - num; |
| /* |
| * Usually we want to free partial cluster at the end of the |
| * extent, except for the situation when the cluster is still |
| * used by any other extent (partial_cluster is negative). |
| */ |
| if (*partial_cluster < 0 && |
| *partial_cluster == -(long long) EXT4_B2C(sbi, pblk+num-1)) |
| flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER; |
| |
| ext_debug("free last %u blocks starting %llu partial %lld\n", |
| num, pblk, *partial_cluster); |
| ext4_free_blocks(handle, inode, NULL, pblk, num, flags); |
| /* |
| * If the block range to be freed didn't start at the |
| * beginning of a cluster, and we removed the entire |
| * extent and the cluster is not used by any other extent, |
| * save the partial cluster here, since we might need to |
| * delete if we determine that the truncate or punch hole |
| * operation has removed all of the blocks in the cluster. |
| * If that cluster is used by another extent, preserve its |
| * negative value so it isn't freed later on. |
| * |
| * If the whole extent wasn't freed, we've reached the |
| * start of the truncated/punched region and have finished |
| * removing blocks. If there's a partial cluster here it's |
| * shared with the remainder of the extent and is no longer |
| * a candidate for removal. |
| */ |
| if (EXT4_PBLK_COFF(sbi, pblk) && ee_len == num) { |
| first_cluster = (long long) EXT4_B2C(sbi, pblk); |
| if (first_cluster != -*partial_cluster) |
| *partial_cluster = first_cluster; |
| } else { |
| *partial_cluster = 0; |
| } |
| } else |
| ext4_error(sbi->s_sb, "strange request: removal(2) " |
| "%u-%u from %u:%u", |
| from, to, le32_to_cpu(ex->ee_block), ee_len); |
| return 0; |
| } |
| |
| |
| /* |
| * ext4_ext_rm_leaf() Removes the extents associated with the |
| * blocks appearing between "start" and "end". Both "start" |
| * and "end" must appear in the same extent or EIO is returned. |
| * |
| * @handle: The journal handle |
| * @inode: The files inode |
| * @path: The path to the leaf |
| * @partial_cluster: The cluster which we'll have to free if all extents |
| * has been released from it. However, if this value is |
| * negative, it's a cluster just to the right of the |
| * punched region and it must not be freed. |
| * @start: The first block to remove |
| * @end: The last block to remove |
| */ |
| static int |
| ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| long long *partial_cluster, |
| ext4_lblk_t start, ext4_lblk_t end) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| int err = 0, correct_index = 0; |
| int depth = ext_depth(inode), credits; |
| struct ext4_extent_header *eh; |
| ext4_lblk_t a, b; |
| unsigned num; |
| ext4_lblk_t ex_ee_block; |
| unsigned short ex_ee_len; |
| unsigned unwritten = 0; |
| struct ext4_extent *ex; |
| ext4_fsblk_t pblk; |
| |
| /* the header must be checked already in ext4_ext_remove_space() */ |
| ext_debug("truncate since %u in leaf to %u\n", start, end); |
| if (!path[depth].p_hdr) |
| path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); |
| eh = path[depth].p_hdr; |
| if (unlikely(path[depth].p_hdr == NULL)) { |
| EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); |
| return -EFSCORRUPTED; |
| } |
| /* find where to start removing */ |
| ex = path[depth].p_ext; |
| if (!ex) |
| ex = EXT_LAST_EXTENT(eh); |
| |
| ex_ee_block = le32_to_cpu(ex->ee_block); |
| ex_ee_len = ext4_ext_get_actual_len(ex); |
| |
| trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster); |
| |
| while (ex >= EXT_FIRST_EXTENT(eh) && |
| ex_ee_block + ex_ee_len > start) { |
| |
| if (ext4_ext_is_unwritten(ex)) |
| unwritten = 1; |
| else |
| unwritten = 0; |
| |
| ext_debug("remove ext %u:[%d]%d\n", ex_ee_block, |
| unwritten, ex_ee_len); |
| path[depth].p_ext = ex; |
| |
| a = ex_ee_block > start ? ex_ee_block : start; |
| b = ex_ee_block+ex_ee_len - 1 < end ? |
| ex_ee_block+ex_ee_len - 1 : end; |
| |
| ext_debug(" border %u:%u\n", a, b); |
| |
| /* If this extent is beyond the end of the hole, skip it */ |
| if (end < ex_ee_block) { |
| /* |
| * We're going to skip this extent and move to another, |
| * so note that its first cluster is in use to avoid |
| * freeing it when removing blocks. Eventually, the |
| * right edge of the truncated/punched region will |
| * be just to the left. |
| */ |
| if (sbi->s_cluster_ratio > 1) { |
| pblk = ext4_ext_pblock(ex); |
| *partial_cluster = |
| -(long long) EXT4_B2C(sbi, pblk); |
| } |
| ex--; |
| ex_ee_block = le32_to_cpu(ex->ee_block); |
| ex_ee_len = ext4_ext_get_actual_len(ex); |
| continue; |
| } else if (b != ex_ee_block + ex_ee_len - 1) { |
| EXT4_ERROR_INODE(inode, |
| "can not handle truncate %u:%u " |
| "on extent %u:%u", |
| start, end, ex_ee_block, |
| ex_ee_block + ex_ee_len - 1); |
| err = -EFSCORRUPTED; |
| goto out; |
| } else if (a != ex_ee_block) { |
| /* remove tail of the extent */ |
| num = a - ex_ee_block; |
| } else { |
| /* remove whole extent: excellent! */ |
| num = 0; |
| } |
| /* |
| * 3 for leaf, sb, and inode plus 2 (bmap and group |
| * descriptor) for each block group; assume two block |
| * groups plus ex_ee_len/blocks_per_block_group for |
| * the worst case |
| */ |
| credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb)); |
| if (ex == EXT_FIRST_EXTENT(eh)) { |
| correct_index = 1; |
| credits += (ext_depth(inode)) + 1; |
| } |
| credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb); |
| |
| err = ext4_ext_truncate_extend_restart(handle, inode, credits); |
| if (err) |
| goto out; |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| err = ext4_remove_blocks(handle, inode, ex, partial_cluster, |
| a, b); |
| if (err) |
| goto out; |
| |
| if (num == 0) |
| /* this extent is removed; mark slot entirely unused */ |
| ext4_ext_store_pblock(ex, 0); |
| |
| ex->ee_len = cpu_to_le16(num); |
| /* |
| * Do not mark unwritten if all the blocks in the |
| * extent have been removed. |
| */ |
| if (unwritten && num) |
| ext4_ext_mark_unwritten(ex); |
| /* |
| * If the extent was completely released, |
| * we need to remove it from the leaf |
| */ |
| if (num == 0) { |
| if (end != EXT_MAX_BLOCKS - 1) { |
| /* |
| * For hole punching, we need to scoot all the |
| * extents up when an extent is removed so that |
| * we dont have blank extents in the middle |
| */ |
| memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) * |
| sizeof(struct ext4_extent)); |
| |
| /* Now get rid of the one at the end */ |
| memset(EXT_LAST_EXTENT(eh), 0, |
| sizeof(struct ext4_extent)); |
| } |
| le16_add_cpu(&eh->eh_entries, -1); |
| } |
| |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num, |
| ext4_ext_pblock(ex)); |
| ex--; |
| ex_ee_block = le32_to_cpu(ex->ee_block); |
| ex_ee_len = ext4_ext_get_actual_len(ex); |
| } |
| |
| if (correct_index && eh->eh_entries) |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| |
| /* |
| * If there's a partial cluster and at least one extent remains in |
| * the leaf, free the partial cluster if it isn't shared with the |
| * current extent. If it is shared with the current extent |
| * we zero partial_cluster because we've reached the start of the |
| * truncated/punched region and we're done removing blocks. |
| */ |
| if (*partial_cluster > 0 && ex >= EXT_FIRST_EXTENT(eh)) { |
| pblk = ext4_ext_pblock(ex) + ex_ee_len - 1; |
| if (*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) { |
| ext4_free_blocks(handle, inode, NULL, |
| EXT4_C2B(sbi, *partial_cluster), |
| sbi->s_cluster_ratio, |
| get_default_free_blocks_flags(inode)); |
| } |
| *partial_cluster = 0; |
| } |
| |
| /* if this leaf is free, then we should |
| * remove it from index block above */ |
| if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) |
| err = ext4_ext_rm_idx(handle, inode, path, depth); |
| |
| out: |
| return err; |
| } |
| |
| /* |
| * ext4_ext_more_to_rm: |
| * returns 1 if current index has to be freed (even partial) |
| */ |
| static int |
| ext4_ext_more_to_rm(struct ext4_ext_path *path) |
| { |
| BUG_ON(path->p_idx == NULL); |
| |
| if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) |
| return 0; |
| |
| /* |
| * if truncate on deeper level happened, it wasn't partial, |
| * so we have to consider current index for truncation |
| */ |
| if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) |
| return 0; |
| return 1; |
| } |
| |
| int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, |
| ext4_lblk_t end) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| int depth = ext_depth(inode); |
| struct ext4_ext_path *path = NULL; |
| long long partial_cluster = 0; |
| handle_t *handle; |
| int i = 0, err = 0; |
| |
| ext_debug("truncate since %u to %u\n", start, end); |
| |
| /* probably first extent we're gonna free will be last in block */ |
| handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1); |
| if (IS_ERR(handle)) |
| return PTR_ERR(handle); |
| |
| again: |
| trace_ext4_ext_remove_space(inode, start, end, depth); |
| |
| /* |
| * Check if we are removing extents inside the extent tree. If that |
| * is the case, we are going to punch a hole inside the extent tree |
| * so we have to check whether we need to split the extent covering |
| * the last block to remove so we can easily remove the part of it |
| * in ext4_ext_rm_leaf(). |
| */ |
| if (end < EXT_MAX_BLOCKS - 1) { |
| struct ext4_extent *ex; |
| ext4_lblk_t ee_block, ex_end, lblk; |
| ext4_fsblk_t pblk; |
| |
| /* find extent for or closest extent to this block */ |
| path = ext4_find_extent(inode, end, NULL, EXT4_EX_NOCACHE); |
| if (IS_ERR(path)) { |
| ext4_journal_stop(handle); |
| return PTR_ERR(path); |
| } |
| depth = ext_depth(inode); |
| /* Leaf not may not exist only if inode has no blocks at all */ |
| ex = path[depth].p_ext; |
| if (!ex) { |
| if (depth) { |
| EXT4_ERROR_INODE(inode, |
| "path[%d].p_hdr == NULL", |
| depth); |
| err = -EFSCORRUPTED; |
| } |
| goto out; |
| } |
| |
| ee_block = le32_to_cpu(ex->ee_block); |
| ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1; |
| |
| /* |
| * See if the last block is inside the extent, if so split |
| * the extent at 'end' block so we can easily remove the |
| * tail of the first part of the split extent in |
| * ext4_ext_rm_leaf(). |
| */ |
| if (end >= ee_block && end < ex_end) { |
| |
| /* |
| * If we're going to split the extent, note that |
| * the cluster containing the block after 'end' is |
| * in use to avoid freeing it when removing blocks. |
| */ |
| if (sbi->s_cluster_ratio > 1) { |
| pblk = ext4_ext_pblock(ex) + end - ee_block + 2; |
| partial_cluster = |
| -(long long) EXT4_B2C(sbi, pblk); |
| } |
| |
| /* |
| * Split the extent in two so that 'end' is the last |
| * block in the first new extent. Also we should not |
| * fail removing space due to ENOSPC so try to use |
| * reserved block if that happens. |
| */ |
| err = ext4_force_split_extent_at(handle, inode, &path, |
| end + 1, 1); |
| if (err < 0) |
| goto out; |
| |
| } else if (sbi->s_cluster_ratio > 1 && end >= ex_end) { |
| /* |
| * If there's an extent to the right its first cluster |
| * contains the immediate right boundary of the |
| * truncated/punched region. Set partial_cluster to |
| * its negative value so it won't be freed if shared |
| * with the current extent. The end < ee_block case |
| * is handled in ext4_ext_rm_leaf(). |
| */ |
| lblk = ex_end + 1; |
| err = ext4_ext_search_right(inode, path, &lblk, &pblk, |
| &ex); |
| if (err) |
| goto out; |
| if (pblk) |
| partial_cluster = |
| -(long long) EXT4_B2C(sbi, pblk); |
| } |
| } |
| /* |
| * We start scanning from right side, freeing all the blocks |
| * after i_size and walking into the tree depth-wise. |
| */ |
| depth = ext_depth(inode); |
| if (path) { |
| int k = i = depth; |
| while (--k > 0) |
| path[k].p_block = |
| le16_to_cpu(path[k].p_hdr->eh_entries)+1; |
| } else { |
| path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), |
| GFP_NOFS); |
| if (path == NULL) { |
| ext4_journal_stop(handle); |
| return -ENOMEM; |
| } |
| path[0].p_maxdepth = path[0].p_depth = depth; |
| path[0].p_hdr = ext_inode_hdr(inode); |
| i = 0; |
| |
| if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) { |
| err = -EFSCORRUPTED; |
| goto out; |
| } |
| } |
| err = 0; |
| |
| while (i >= 0 && err == 0) { |
| if (i == depth) { |
| /* this is leaf block */ |
| err = ext4_ext_rm_leaf(handle, inode, path, |
| &partial_cluster, start, |
| end); |
| /* root level has p_bh == NULL, brelse() eats this */ |
| brelse(path[i].p_bh); |
| path[i].p_bh = NULL; |
| i--; |
| continue; |
| } |
| |
| /* this is index block */ |
| if (!path[i].p_hdr) { |
| ext_debug("initialize header\n"); |
| path[i].p_hdr = ext_block_hdr(path[i].p_bh); |
| } |
| |
| if (!path[i].p_idx) { |
| /* this level hasn't been touched yet */ |
| path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); |
| path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; |
| ext_debug("init index ptr: hdr 0x%p, num %d\n", |
| path[i].p_hdr, |
| le16_to_cpu(path[i].p_hdr->eh_entries)); |
| } else { |
| /* we were already here, see at next index */ |
| path[i].p_idx--; |
| } |
| |
| ext_debug("level %d - index, first 0x%p, cur 0x%p\n", |
| i, EXT_FIRST_INDEX(path[i].p_hdr), |
| path[i].p_idx); |
| if (ext4_ext_more_to_rm(path + i)) { |
| struct buffer_head *bh; |
| /* go to the next level */ |
| ext_debug("move to level %d (block %llu)\n", |
| i + 1, ext4_idx_pblock(path[i].p_idx)); |
| memset(path + i + 1, 0, sizeof(*path)); |
| bh = read_extent_tree_block(inode, |
| ext4_idx_pblock(path[i].p_idx), depth - i - 1, |
| EXT4_EX_NOCACHE); |
| if (IS_ERR(bh)) { |
| /* should we reset i_size? */ |
| err = PTR_ERR(bh); |
| break; |
| } |
| /* Yield here to deal with large extent trees. |
| * Should be a no-op if we did IO above. */ |
| cond_resched(); |
| if (WARN_ON(i + 1 > depth)) { |
| err = -EFSCORRUPTED; |
| break; |
| } |
| path[i + 1].p_bh = bh; |
| |
| /* save actual number of indexes since this |
| * number is changed at the next iteration */ |
| path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); |
| i++; |
| } else { |
| /* we finished processing this index, go up */ |
| if (path[i].p_hdr->eh_entries == 0 && i > 0) { |
| /* index is empty, remove it; |
| * handle must be already prepared by the |
| * truncatei_leaf() */ |
| err = ext4_ext_rm_idx(handle, inode, path, i); |
| } |
| /* root level has p_bh == NULL, brelse() eats this */ |
| brelse(path[i].p_bh); |
| path[i].p_bh = NULL; |
| i--; |
| ext_debug("return to level %d\n", i); |
| } |
| } |
| |
| trace_ext4_ext_remove_space_done(inode, start, end, depth, |
| partial_cluster, path->p_hdr->eh_entries); |
| |
| /* |
| * If we still have something in the partial cluster and we have removed |
| * even the first extent, then we should free the blocks in the partial |
| * cluster as well. (This code will only run when there are no leaves |
| * to the immediate left of the truncated/punched region.) |
| */ |
| if (partial_cluster > 0 && err == 0) { |
| /* don't zero partial_cluster since it's not used afterwards */ |
| ext4_free_blocks(handle, inode, NULL, |
| EXT4_C2B(sbi, partial_cluster), |
| sbi->s_cluster_ratio, |
| get_default_free_blocks_flags(inode)); |
| } |
| |
| /* TODO: flexible tree reduction should be here */ |
| if (path->p_hdr->eh_entries == 0) { |
| /* |
| * truncate to zero freed all the tree, |
| * so we need to correct eh_depth |
| */ |
| err = ext4_ext_get_access(handle, inode, path); |
| if (err == 0) { |
| ext_inode_hdr(inode)->eh_depth = 0; |
| ext_inode_hdr(inode)->eh_max = |
| cpu_to_le16(ext4_ext_space_root(inode, 0)); |
| err = ext4_ext_dirty(handle, inode, path); |
| } |
| } |
| out: |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| path = NULL; |
| if (err == -EAGAIN) |
| goto again; |
| ext4_journal_stop(handle); |
| |
| return err; |
| } |
| |
| /* |
| * called at mount time |
| */ |
| void ext4_ext_init(struct super_block *sb) |
| { |
| /* |
| * possible initialization would be here |
| */ |
| |
| if (ext4_has_feature_extents(sb)) { |
| #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS) |
| printk(KERN_INFO "EXT4-fs: file extents enabled" |
| #ifdef AGGRESSIVE_TEST |
| ", aggressive tests" |
| #endif |
| #ifdef CHECK_BINSEARCH |
| ", check binsearch" |
| #endif |
| #ifdef EXTENTS_STATS |
| ", stats" |
| #endif |
| "\n"); |
| #endif |
| #ifdef EXTENTS_STATS |
| spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); |
| EXT4_SB(sb)->s_ext_min = 1 << 30; |
| EXT4_SB(sb)->s_ext_max = 0; |
| #endif |
| } |
| } |
| |
| /* |
| * called at umount time |
| */ |
| void ext4_ext_release(struct super_block *sb) |
| { |
| if (!ext4_has_feature_extents(sb)) |
| return; |
| |
| #ifdef EXTENTS_STATS |
| if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", |
| sbi->s_ext_blocks, sbi->s_ext_extents, |
| sbi->s_ext_blocks / sbi->s_ext_extents); |
| printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", |
| sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); |
| } |
| #endif |
| } |
| |
| static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex) |
| { |
| ext4_lblk_t ee_block; |
| ext4_fsblk_t ee_pblock; |
| unsigned int ee_len; |
| |
| ee_block = le32_to_cpu(ex->ee_block); |
| ee_len = ext4_ext_get_actual_len(ex); |
| ee_pblock = ext4_ext_pblock(ex); |
| |
| if (ee_len == 0) |
| return 0; |
| |
| return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock, |
| EXTENT_STATUS_WRITTEN); |
| } |
| |
| /* FIXME!! we need to try to merge to left or right after zero-out */ |
| static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) |
| { |
| ext4_fsblk_t ee_pblock; |
| unsigned int ee_len; |
| |
| ee_len = ext4_ext_get_actual_len(ex); |
| ee_pblock = ext4_ext_pblock(ex); |
| return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock, |
| ee_len); |
| } |
| |
| /* |
| * ext4_split_extent_at() splits an extent at given block. |
| * |
| * @handle: the journal handle |
| * @inode: the file inode |
| * @path: the path to the extent |
| * @split: the logical block where the extent is splitted. |
| * @split_flags: indicates if the extent could be zeroout if split fails, and |
| * the states(init or unwritten) of new extents. |
| * @flags: flags used to insert new extent to extent tree. |
| * |
| * |
| * Splits extent [a, b] into two extents [a, @split) and [@split, b], states |
| * of which are deterimined by split_flag. |
| * |
| * There are two cases: |
| * a> the extent are splitted into two extent. |
| * b> split is not needed, and just mark the extent. |
| * |
| * return 0 on success. |
| */ |
| static int ext4_split_extent_at(handle_t *handle, |
| struct inode *inode, |
| struct ext4_ext_path **ppath, |
| ext4_lblk_t split, |
| int split_flag, |
| int flags) |
| { |
| struct ext4_ext_path *path = *ppath; |
| ext4_fsblk_t newblock; |
| ext4_lblk_t ee_block; |
| struct ext4_extent *ex, newex, orig_ex, zero_ex; |
| struct ext4_extent *ex2 = NULL; |
| unsigned int ee_len, depth; |
| int err = 0; |
| |
| BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) == |
| (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)); |
| |
| ext_debug("ext4_split_extents_at: inode %lu, logical" |
| "block %llu\n", inode->i_ino, (unsigned long long)split); |
| |
| ext4_ext_show_leaf(inode, path); |
| |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| ee_block = le32_to_cpu(ex->ee_block); |
| ee_len = ext4_ext_get_actual_len(ex); |
| newblock = split - ee_block + ext4_ext_pblock(ex); |
| |
| BUG_ON(split < ee_block || split >= (ee_block + ee_len)); |
| BUG_ON(!ext4_ext_is_unwritten(ex) && |
| split_flag & (EXT4_EXT_MAY_ZEROOUT | |
| EXT4_EXT_MARK_UNWRIT1 | |
| EXT4_EXT_MARK_UNWRIT2)); |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| if (split == ee_block) { |
| /* |
| * case b: block @split is the block that the extent begins with |
| * then we just change the state of the extent, and splitting |
| * is not needed. |
| */ |
| if (split_flag & EXT4_EXT_MARK_UNWRIT2) |
| ext4_ext_mark_unwritten(ex); |
| else |
| ext4_ext_mark_initialized(ex); |
| |
| if (!(flags & EXT4_GET_BLOCKS_PRE_IO)) |
| ext4_ext_try_to_merge(handle, inode, path, ex); |
| |
| err = ext4_ext_dirty(handle, inode, path + path->p_depth); |
| goto out; |
| } |
| |
| /* case a */ |
| memcpy(&orig_ex, ex, sizeof(orig_ex)); |
| ex->ee_len = cpu_to_le16(split - ee_block); |
| if (split_flag & EXT4_EXT_MARK_UNWRIT1) |
| ext4_ext_mark_unwritten(ex); |
| |
| /* |
| * path may lead to new leaf, not to original leaf any more |
| * after ext4_ext_insert_extent() returns, |
| */ |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| if (err) |
| goto fix_extent_len; |
| |
| ex2 = &newex; |
| ex2->ee_block = cpu_to_le32(split); |
| ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block)); |
| ext4_ext_store_pblock(ex2, newblock); |
| if (split_flag & EXT4_EXT_MARK_UNWRIT2) |
| ext4_ext_mark_unwritten(ex2); |
| |
| err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags); |
| if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) { |
| if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) { |
| if (split_flag & EXT4_EXT_DATA_VALID1) { |
| err = ext4_ext_zeroout(inode, ex2); |
| zero_ex.ee_block = ex2->ee_block; |
| zero_ex.ee_len = cpu_to_le16( |
| ext4_ext_get_actual_len(ex2)); |
| ext4_ext_store_pblock(&zero_ex, |
| ext4_ext_pblock(ex2)); |
| } else { |
| err = ext4_ext_zeroout(inode, ex); |
| zero_ex.ee_block = ex->ee_block; |
| zero_ex.ee_len = cpu_to_le16( |
| ext4_ext_get_actual_len(ex)); |
| ext4_ext_store_pblock(&zero_ex, |
| ext4_ext_pblock(ex)); |
| } |
| } else { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| zero_ex.ee_block = orig_ex.ee_block; |
| zero_ex.ee_len = cpu_to_le16( |
| ext4_ext_get_actual_len(&orig_ex)); |
| ext4_ext_store_pblock(&zero_ex, |
| ext4_ext_pblock(&orig_ex)); |
| } |
| |
| if (err) |
| goto fix_extent_len; |
| /* update the extent length and mark as initialized */ |
| ex->ee_len = cpu_to_le16(ee_len); |
| ext4_ext_try_to_merge(handle, inode, path, ex); |
| err = ext4_ext_dirty(handle, inode, path + path->p_depth); |
| if (err) |
| goto fix_extent_len; |
| |
| /* update extent status tree */ |
| err = ext4_zeroout_es(inode, &zero_ex); |
| |
| goto out; |
| } else if (err) |
| goto fix_extent_len; |
| |
| out: |
| ext4_ext_show_leaf(inode, path); |
| return err; |
| |
| fix_extent_len: |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_dirty(handle, inode, path + path->p_depth); |
| return err; |
| } |
| |
| /* |
| * ext4_split_extents() splits an extent and mark extent which is covered |
| * by @map as split_flags indicates |
| * |
| * It may result in splitting the extent into multiple extents (up to three) |
| * There are three possibilities: |
| * a> There is no split required |
| * b> Splits in two extents: Split is happening at either end of the extent |
| * c> Splits in three extents: Somone is splitting in middle of the extent |
| * |
| */ |
| static int ext4_split_extent(handle_t *handle, |
| struct inode *inode, |
| struct ext4_ext_path **ppath, |
| struct ext4_map_blocks *map, |
| int split_flag, |
| int flags) |
| { |
| struct ext4_ext_path *path = *ppath; |
| ext4_lblk_t ee_block; |
| struct ext4_extent *ex; |
| unsigned int ee_len, depth; |
| int err = 0; |
| int unwritten; |
| int split_flag1, flags1; |
| int allocated = map->m_len; |
| |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| ee_block = le32_to_cpu(ex->ee_block); |
| ee_len = ext4_ext_get_actual_len(ex); |
| unwritten = ext4_ext_is_unwritten(ex); |
| |
| if (map->m_lblk + map->m_len < ee_block + ee_len) { |
| split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT; |
| flags1 = flags | EXT4_GET_BLOCKS_PRE_IO; |
| if (unwritten) |
| split_flag1 |= EXT4_EXT_MARK_UNWRIT1 | |
| EXT4_EXT_MARK_UNWRIT2; |
| if (split_flag & EXT4_EXT_DATA_VALID2) |
| split_flag1 |= EXT4_EXT_DATA_VALID1; |
| err = ext4_split_extent_at(handle, inode, ppath, |
| map->m_lblk + map->m_len, split_flag1, flags1); |
| if (err) |
| goto out; |
| } else { |
| allocated = ee_len - (map->m_lblk - ee_block); |
| } |
| /* |
| * Update path is required because previous ext4_split_extent_at() may |
| * result in split of original leaf or extent zeroout. |
| */ |
| path = ext4_find_extent(inode, map->m_lblk, ppath, 0); |
| if (IS_ERR(path)) |
| return PTR_ERR(path); |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| if (!ex) { |
| EXT4_ERROR_INODE(inode, "unexpected hole at %lu", |
| (unsigned long) map->m_lblk); |
| return -EFSCORRUPTED; |
| } |
| unwritten = ext4_ext_is_unwritten(ex); |
| split_flag1 = 0; |
| |
| if (map->m_lblk >= ee_block) { |
| split_flag1 = split_flag & EXT4_EXT_DATA_VALID2; |
| if (unwritten) { |
| split_flag1 |= EXT4_EXT_MARK_UNWRIT1; |
| split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT | |
| EXT4_EXT_MARK_UNWRIT2); |
| } |
| err = ext4_split_extent_at(handle, inode, ppath, |
| map->m_lblk, split_flag1, flags); |
| if (err) |
| goto out; |
| } |
| |
| ext4_ext_show_leaf(inode, path); |
| out: |
| return err ? err : allocated; |
| } |
| |
| /* |
| * This function is called by ext4_ext_map_blocks() if someone tries to write |
| * to an unwritten extent. It may result in splitting the unwritten |
| * extent into multiple extents (up to three - one initialized and two |
| * unwritten). |
| * There are three possibilities: |
| * a> There is no split required: Entire extent should be initialized |
| * b> Splits in two extents: Write is happening at either end of the extent |
| * c> Splits in three extents: Somone is writing in middle of the extent |
| * |
| * Pre-conditions: |
| * - The extent pointed to by 'path' is unwritten. |
| * - The extent pointed to by 'path' contains a superset |
| * of the logical span [map->m_lblk, map->m_lblk + map->m_len). |
| * |
| * Post-conditions on success: |
| * - the returned value is the number of blocks beyond map->l_lblk |
| * that are allocated and initialized. |
| * It is guaranteed to be >= map->m_len. |
| */ |
| static int ext4_ext_convert_to_initialized(handle_t *handle, |
| struct inode *inode, |
| struct ext4_map_blocks *map, |
| struct ext4_ext_path **ppath, |
| int flags) |
| { |
| struct ext4_ext_path *path = *ppath; |
| struct ext4_sb_info *sbi; |
| struct ext4_extent_header *eh; |
| struct ext4_map_blocks split_map; |
| struct ext4_extent zero_ex1, zero_ex2; |
| struct ext4_extent *ex, *abut_ex; |
| ext4_lblk_t ee_block, eof_block; |
| unsigned int ee_len, depth, map_len = map->m_len; |
| int allocated = 0, max_zeroout = 0; |
| int err = 0; |
| int split_flag = EXT4_EXT_DATA_VALID2; |
| |
| ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical" |
| "block %llu, max_blocks %u\n", inode->i_ino, |
| (unsigned long long)map->m_lblk, map_len); |
| |
| sbi = EXT4_SB(inode->i_sb); |
| eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> |
| inode->i_sb->s_blocksize_bits; |
| if (eof_block < map->m_lblk + map_len) |
| eof_block = map->m_lblk + map_len; |
| |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| ex = path[depth].p_ext; |
| ee_block = le32_to_cpu(ex->ee_block); |
| ee_len = ext4_ext_get_actual_len(ex); |
| zero_ex1.ee_len = 0; |
| zero_ex2.ee_len = 0; |
| |
| trace_ext4_ext_convert_to_initialized_enter(inode, map, ex); |
| |
| /* Pre-conditions */ |
| BUG_ON(!ext4_ext_is_unwritten(ex)); |
| BUG_ON(!in_range(map->m_lblk, ee_block, ee_len)); |
| |
| /* |
| * Attempt to transfer newly initialized blocks from the currently |
| * unwritten extent to its neighbor. This is much cheaper |
| * than an insertion followed by a merge as those involve costly |
| * memmove() calls. Transferring to the left is the common case in |
| * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE) |
| * followed by append writes. |
| * |
| * Limitations of the current logic: |
| * - L1: we do not deal with writes covering the whole extent. |
| * This would require removing the extent if the transfer |
| * is possible. |
| * - L2: we only attempt to merge with an extent stored in the |
| * same extent tree node. |
| */ |
| if ((map->m_lblk == ee_block) && |
| /* See if we can merge left */ |
| (map_len < ee_len) && /*L1*/ |
| (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/ |
| ext4_lblk_t prev_lblk; |
| ext4_fsblk_t prev_pblk, ee_pblk; |
| unsigned int prev_len; |
| |
| abut_ex = ex - 1; |
| prev_lblk = le32_to_cpu(abut_ex->ee_block); |
| prev_len = ext4_ext_get_actual_len(abut_ex); |
| prev_pblk = ext4_ext_pblock(abut_ex); |
| ee_pblk = ext4_ext_pblock(ex); |
| |
| /* |
| * A transfer of blocks from 'ex' to 'abut_ex' is allowed |
| * upon those conditions: |
| * - C1: abut_ex is initialized, |
| * - C2: abut_ex is logically abutting ex, |
| * - C3: abut_ex is physically abutting ex, |
| * - C4: abut_ex can receive the additional blocks without |
| * overflowing the (initialized) length limit. |
| */ |
| if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/ |
| ((prev_lblk + prev_len) == ee_block) && /*C2*/ |
| ((prev_pblk + prev_len) == ee_pblk) && /*C3*/ |
| (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/ |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| trace_ext4_ext_convert_to_initialized_fastpath(inode, |
| map, ex, abut_ex); |
| |
| /* Shift the start of ex by 'map_len' blocks */ |
| ex->ee_block = cpu_to_le32(ee_block + map_len); |
| ext4_ext_store_pblock(ex, ee_pblk + map_len); |
| ex->ee_len = cpu_to_le16(ee_len - map_len); |
| ext4_ext_mark_unwritten(ex); /* Restore the flag */ |
| |
| /* Extend abut_ex by 'map_len' blocks */ |
| abut_ex->ee_len = cpu_to_le16(prev_len + map_len); |
| |
| /* Result: number of initialized blocks past m_lblk */ |
| allocated = map_len; |
| } |
| } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) && |
| (map_len < ee_len) && /*L1*/ |
| ex < EXT_LAST_EXTENT(eh)) { /*L2*/ |
| /* See if we can merge right */ |
| ext4_lblk_t next_lblk; |
| ext4_fsblk_t next_pblk, ee_pblk; |
| unsigned int next_len; |
| |
| abut_ex = ex + 1; |
| next_lblk = le32_to_cpu(abut_ex->ee_block); |
| next_len = ext4_ext_get_actual_len(abut_ex); |
| next_pblk = ext4_ext_pblock(abut_ex); |
| ee_pblk = ext4_ext_pblock(ex); |
| |
| /* |
| * A transfer of blocks from 'ex' to 'abut_ex' is allowed |
| * upon those conditions: |
| * - C1: abut_ex is initialized, |
| * - C2: abut_ex is logically abutting ex, |
| * - C3: abut_ex is physically abutting ex, |
| * - C4: abut_ex can receive the additional blocks without |
| * overflowing the (initialized) length limit. |
| */ |
| if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/ |
| ((map->m_lblk + map_len) == next_lblk) && /*C2*/ |
| ((ee_pblk + ee_len) == next_pblk) && /*C3*/ |
| (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/ |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| trace_ext4_ext_convert_to_initialized_fastpath(inode, |
| map, ex, abut_ex); |
| |
| /* Shift the start of abut_ex by 'map_len' blocks */ |
| abut_ex->ee_block = cpu_to_le32(next_lblk - map_len); |
| ext4_ext_store_pblock(abut_ex, next_pblk - map_len); |
| ex->ee_len = cpu_to_le16(ee_len - map_len); |
| ext4_ext_mark_unwritten(ex); /* Restore the flag */ |
| |
| /* Extend abut_ex by 'map_len' blocks */ |
| abut_ex->ee_len = cpu_to_le16(next_len + map_len); |
| |
| /* Result: number of initialized blocks past m_lblk */ |
| allocated = map_len; |
| } |
| } |
| if (allocated) { |
| /* Mark the block containing both extents as dirty */ |
| ext4_ext_dirty(handle, inode, path + depth); |
| |
| /* Update path to point to the right extent */ |
| path[depth].p_ext = abut_ex; |
| goto out; |
| } else |
| allocated = ee_len - (map->m_lblk - ee_block); |
| |
| WARN_ON(map->m_lblk < ee_block); |
| /* |
| * It is safe to convert extent to initialized via explicit |
| * zeroout only if extent is fully inside i_size or new_size. |
| */ |
| split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0; |
| |
| if (EXT4_EXT_MAY_ZEROOUT & split_flag) |
| max_zeroout = sbi->s_extent_max_zeroout_kb >> |
| (inode->i_sb->s_blocksize_bits - 10); |
| |
| if (ext4_encrypted_inode(inode)) |
| max_zeroout = 0; |
| |
| /* |
| * five cases: |
| * 1. split the extent into three extents. |
| * 2. split the extent into two extents, zeroout the head of the first |
| * extent. |
| * 3. split the extent into two extents, zeroout the tail of the second |
| * extent. |
| * 4. split the extent into two extents with out zeroout. |
| * 5. no splitting needed, just possibly zeroout the head and / or the |
| * tail of the extent. |
| */ |
| split_map.m_lblk = map->m_lblk; |
| split_map.m_len = map->m_len; |
| |
| if (max_zeroout && (allocated > split_map.m_len)) { |
| if (allocated <= max_zeroout) { |
| /* case 3 or 5 */ |
| zero_ex1.ee_block = |
| cpu_to_le32(split_map.m_lblk + |
| split_map.m_len); |
| zero_ex1.ee_len = |
| cpu_to_le16(allocated - split_map.m_len); |
| ext4_ext_store_pblock(&zero_ex1, |
| ext4_ext_pblock(ex) + split_map.m_lblk + |
| split_map.m_len - ee_block); |
| err = ext4_ext_zeroout(inode, &zero_ex1); |
| if (err) |
| goto out; |
| split_map.m_len = allocated; |
| } |
| if (split_map.m_lblk - ee_block + split_map.m_len < |
| max_zeroout) { |
| /* case 2 or 5 */ |
| if (split_map.m_lblk != ee_block) { |
| zero_ex2.ee_block = ex->ee_block; |
| zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk - |
| ee_block); |
| ext4_ext_store_pblock(&zero_ex2, |
| ext4_ext_pblock(ex)); |
| err = ext4_ext_zeroout(inode, &zero_ex2); |
| if (err) |
| goto out; |
| } |
| |
| split_map.m_len += split_map.m_lblk - ee_block; |
| split_map.m_lblk = ee_block; |
| allocated = map->m_len; |
| } |
| } |
| |
| err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag, |
| flags); |
| if (err > 0) |
| err = 0; |
| out: |
| /* If we have gotten a failure, don't zero out status tree */ |
| if (!err) { |
| err = ext4_zeroout_es(inode, &zero_ex1); |
| if (!err) |
| err = ext4_zeroout_es(inode, &zero_ex2); |
| } |
| return err ? err : allocated; |
| } |
| |
| /* |
| * This function is called by ext4_ext_map_blocks() from |
| * ext4_get_blocks_dio_write() when DIO to write |
| * to an unwritten extent. |
| * |
| * Writing to an unwritten extent may result in splitting the unwritten |
| * extent into multiple initialized/unwritten extents (up to three) |
| * There are three possibilities: |
| * a> There is no split required: Entire extent should be unwritten |
| * b> Splits in two extents: Write is happening at either end of the extent |
| * c> Splits in three extents: Somone is writing in middle of the extent |
| * |
| * This works the same way in the case of initialized -> unwritten conversion. |
| * |
| * One of more index blocks maybe needed if the extent tree grow after |
| * the unwritten extent split. To prevent ENOSPC occur at the IO |
| * complete, we need to split the unwritten extent before DIO submit |
| * the IO. The unwritten extent called at this time will be split |
| * into three unwritten extent(at most). After IO complete, the part |
| * being filled will be convert to initialized by the end_io callback function |
| * via ext4_convert_unwritten_extents(). |
| * |
| * Returns the size of unwritten extent to be written on success. |
| */ |
| static int ext4_split_convert_extents(handle_t *handle, |
| struct inode *inode, |
| struct ext4_map_blocks *map, |
| struct ext4_ext_path **ppath, |
| int flags) |
| { |
| struct ext4_ext_path *path = *ppath; |
| ext4_lblk_t eof_block; |
| ext4_lblk_t ee_block; |
| struct ext4_extent *ex; |
| unsigned int ee_len; |
| int split_flag = 0, depth; |
| |
| ext_debug("%s: inode %lu, logical block %llu, max_blocks %u\n", |
| __func__, inode->i_ino, |
| (unsigned long long)map->m_lblk, map->m_len); |
| |
| eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> |
| inode->i_sb->s_blocksize_bits; |
| if (eof_block < map->m_lblk + map->m_len) |
| eof_block = map->m_lblk + map->m_len; |
| /* |
| * It is safe to convert extent to initialized via explicit |
| * zeroout only if extent is fully insde i_size or new_size. |
| */ |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| ee_block = le32_to_cpu(ex->ee_block); |
| ee_len = ext4_ext_get_actual_len(ex); |
| |
| /* Convert to unwritten */ |
| if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) { |
| split_flag |= EXT4_EXT_DATA_VALID1; |
| /* Convert to initialized */ |
| } else if (flags & EXT4_GET_BLOCKS_CONVERT) { |
| split_flag |= ee_block + ee_len <= eof_block ? |
| EXT4_EXT_MAY_ZEROOUT : 0; |
| split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2); |
| } |
| flags |= EXT4_GET_BLOCKS_PRE_IO; |
| return ext4_split_extent(handle, inode, ppath, map, split_flag, flags); |
| } |
| |
| static int ext4_convert_unwritten_extents_endio(handle_t *handle, |
| struct inode *inode, |
| struct ext4_map_blocks *map, |
| struct ext4_ext_path **ppath) |
| { |
| struct ext4_ext_path *path = *ppath; |
| struct ext4_extent *ex; |
| ext4_lblk_t ee_block; |
| unsigned int ee_len; |
| int depth; |
| int err = 0; |
| |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| ee_block = le32_to_cpu(ex->ee_block); |
| ee_len = ext4_ext_get_actual_len(ex); |
| |
| ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical" |
| "block %llu, max_blocks %u\n", inode->i_ino, |
| (unsigned long long)ee_block, ee_len); |
| |
| /* If extent is larger than requested it is a clear sign that we still |
| * have some extent state machine issues left. So extent_split is still |
| * required. |
| * TODO: Once all related issues will be fixed this situation should be |
| * illegal. |
| */ |
| if (ee_block != map->m_lblk || ee_len > map->m_len) { |
| #ifdef CONFIG_EXT4_DEBUG |
| ext4_warning(inode->i_sb, "Inode (%ld) finished: extent logical block %llu," |
| " len %u; IO logical block %llu, len %u", |
| inode->i_ino, (unsigned long long)ee_block, ee_len, |
| (unsigned long long)map->m_lblk, map->m_len); |
| #endif |
| err = ext4_split_convert_extents(handle, inode, map, ppath, |
| EXT4_GET_BLOCKS_CONVERT); |
| if (err < 0) |
| return err; |
| path = ext4_find_extent(inode, map->m_lblk, ppath, 0); |
| if (IS_ERR(path)) |
| return PTR_ERR(path); |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| } |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| /* first mark the extent as initialized */ |
| ext4_ext_mark_initialized(ex); |
| |
| /* note: ext4_ext_correct_indexes() isn't needed here because |
| * borders are not changed |
| */ |
| ext4_ext_try_to_merge(handle, inode, path, ex); |
| |
| /* Mark modified extent as dirty */ |
| err = ext4_ext_dirty(handle, inode, path + path->p_depth); |
| out: |
| ext4_ext_show_leaf(inode, path); |
| return err; |
| } |
| |
| static void unmap_underlying_metadata_blocks(struct block_device *bdev, |
| sector_t block, int count) |
| { |
| int i; |
| for (i = 0; i < count; i++) |
| unmap_underlying_metadata(bdev, block + i); |
| } |
| |
| /* |
| * Handle EOFBLOCKS_FL flag, clearing it if necessary |
| */ |
| static int check_eofblocks_fl(handle_t *handle, struct inode *inode, |
| ext4_lblk_t lblk, |
| struct ext4_ext_path *path, |
| unsigned int len) |
| { |
| int i, depth; |
| struct ext4_extent_header *eh; |
| struct ext4_extent *last_ex; |
| |
| if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)) |
| return 0; |
| |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| |
| /* |
| * We're going to remove EOFBLOCKS_FL entirely in future so we |
| * do not care for this case anymore. Simply remove the flag |
| * if there are no extents. |
| */ |
| if (unlikely(!eh->eh_entries)) |
| goto out; |
| last_ex = EXT_LAST_EXTENT(eh); |
| /* |
| * We should clear the EOFBLOCKS_FL flag if we are writing the |
| * last block in the last extent in the file. We test this by |
| * first checking to see if the caller to |
| * ext4_ext_get_blocks() was interested in the last block (or |
| * a block beyond the last block) in the current extent. If |
| * this turns out to be false, we can bail out from this |
| * function immediately. |
| */ |
| if (lblk + len < le32_to_cpu(last_ex->ee_block) + |
| ext4_ext_get_actual_len(last_ex)) |
| return 0; |
| /* |
| * If the caller does appear to be planning to write at or |
| * beyond the end of the current extent, we then test to see |
| * if the current extent is the last extent in the file, by |
| * checking to make sure it was reached via the rightmost node |
| * at each level of the tree. |
| */ |
| for (i = depth-1; i >= 0; i--) |
| if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr)) |
| return 0; |
| out: |
| ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS); |
| return ext4_mark_inode_dirty(handle, inode); |
| } |
| |
| /** |
| * ext4_find_delalloc_range: find delayed allocated block in the given range. |
| * |
| * Return 1 if there is a delalloc block in the range, otherwise 0. |
| */ |
| int ext4_find_delalloc_range(struct inode *inode, |
| ext4_lblk_t lblk_start, |
| ext4_lblk_t lblk_end) |
| { |
| struct extent_status es; |
| |
| ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es); |
| if (es.es_len == 0) |
| return 0; /* there is no delay extent in this tree */ |
| else if (es.es_lblk <= lblk_start && |
| lblk_start < es.es_lblk + es.es_len) |
| return 1; |
| else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end) |
| return 1; |
| else |
| return 0; |
| } |
| |
| int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| ext4_lblk_t lblk_start, lblk_end; |
| lblk_start = EXT4_LBLK_CMASK(sbi, lblk); |
| lblk_end = lblk_start + sbi->s_cluster_ratio - 1; |
| |
| return ext4_find_delalloc_range(inode, lblk_start, lblk_end); |
| } |
| |
| /** |
| * Determines how many complete clusters (out of those specified by the 'map') |
| * are under delalloc and were reserved quota for. |
| * This function is called when we are writing out the blocks that were |
| * originally written with their allocation delayed, but then the space was |
| * allocated using fallocate() before the delayed allocation could be resolved. |
| * The cases to look for are: |
| * ('=' indicated delayed allocated blocks |
| * '-' indicates non-delayed allocated blocks) |
| * (a) partial clusters towards beginning and/or end outside of allocated range |
| * are not delalloc'ed. |
| * Ex: |
| * |----c---=|====c====|====c====|===-c----| |
| * |++++++ allocated ++++++| |
| * ==> 4 complete clusters in above example |
| * |
| * (b) partial cluster (outside of allocated range) towards either end is |
| * marked for delayed allocation. In this case, we will exclude that |
| * cluster. |
| * Ex: |
| * |----====c========|========c========| |
| * |++++++ allocated ++++++| |
| * ==> 1 complete clusters in above example |
| * |
| * Ex: |
| * |================c================| |
| * |++++++ allocated ++++++| |
| * ==> 0 complete clusters in above example |
| * |
| * The ext4_da_update_reserve_space will be called only if we |
| * determine here that there were some "entire" clusters that span |
| * this 'allocated' range. |
| * In the non-bigalloc case, this function will just end up returning num_blks |
| * without ever calling ext4_find_delalloc_range. |
| */ |
| static unsigned int |
| get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start, |
| unsigned int num_blks) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| ext4_lblk_t alloc_cluster_start, alloc_cluster_end; |
| ext4_lblk_t lblk_from, lblk_to, c_offset; |
| unsigned int allocated_clusters = 0; |
| |
| alloc_cluster_start = EXT4_B2C(sbi, lblk_start); |
| alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1); |
| |
| /* max possible clusters for this allocation */ |
| allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1; |
| |
| trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks); |
| |
| /* Check towards left side */ |
| c_offset = EXT4_LBLK_COFF(sbi, lblk_start); |
| if (c_offset) { |
| lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start); |
| lblk_to = lblk_from + c_offset - 1; |
| |
| if (ext4_find_delalloc_range(inode, lblk_from, lblk_to)) |
| allocated_clusters--; |
| } |
| |
| /* Now check towards right. */ |
| c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks); |
| if (allocated_clusters && c_offset) { |
| lblk_from = lblk_start + num_blks; |
| lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1; |
| |
| if (ext4_find_delalloc_range(inode, lblk_from, lblk_to)) |
| allocated_clusters--; |
| } |
| |
| return allocated_clusters; |
| } |
| |
| static int |
| convert_initialized_extent(handle_t *handle, struct inode *inode, |
| struct ext4_map_blocks *map, |
| struct ext4_ext_path **ppath, |
| unsigned int allocated) |
| { |
| struct ext4_ext_path *path = *ppath; |
| struct ext4_extent *ex; |
| ext4_lblk_t ee_block; |
| unsigned int ee_len; |
| int depth; |
| int err = 0; |
| |
| /* |
| * Make sure that the extent is no bigger than we support with |
| * unwritten extent |
| */ |
| if (map->m_len > EXT_UNWRITTEN_MAX_LEN) |
| map->m_len = EXT_UNWRITTEN_MAX_LEN / 2; |
| |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| ee_block = le32_to_cpu(ex->ee_block); |
| ee_len = ext4_ext_get_actual_len(ex); |
| |
| ext_debug("%s: inode %lu, logical" |
| "block %llu, max_blocks %u\n", __func__, inode->i_ino, |
| (unsigned long long)ee_block, ee_len); |
| |
| if (ee_block != map->m_lblk || ee_len > map->m_len) { |
| err = ext4_split_convert_extents(handle, inode, map, ppath, |
| EXT4_GET_BLOCKS_CONVERT_UNWRITTEN); |
| if (err < 0) |
| return err; |
| path = ext4_find_extent(inode, map->m_lblk, ppath, 0); |
| if (IS_ERR(path)) |
| return PTR_ERR(path); |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| if (!ex) { |
| EXT4_ERROR_INODE(inode, "unexpected hole at %lu", |
| (unsigned long) map->m_lblk); |
| return -EFSCORRUPTED; |
| } |
| } |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| return err; |
| /* first mark the extent as unwritten */ |
| ext4_ext_mark_unwritten(ex); |
| |
| /* note: ext4_ext_correct_indexes() isn't needed here because |
| * borders are not changed |
| */ |
| ext4_ext_try_to_merge(handle, inode, path, ex); |
| |
| /* Mark modified extent as dirty */ |
| err = ext4_ext_dirty(handle, inode, path + path->p_depth); |
| if (err) |
| return err; |
| ext4_ext_show_leaf(inode, path); |
| |
| ext4_update_inode_fsync_trans(handle, inode, 1); |
| err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len); |
| if (err) |
| return err; |
| map->m_flags |= EXT4_MAP_UNWRITTEN; |
| if (allocated > map->m_len) |
| allocated = map->m_len; |
| map->m_len = allocated; |
| return allocated; |
| } |
| |
| static int |
| ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, |
| struct ext4_map_blocks *map, |
| struct ext4_ext_path **ppath, int flags, |
| unsigned int allocated, ext4_fsblk_t newblock) |
| { |
| struct ext4_ext_path *path = *ppath; |
| int ret = 0; |
| int err = 0; |
| |
| ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical " |
| "block %llu, max_blocks %u, flags %x, allocated %u\n", |
| inode->i_ino, (unsigned long long)map->m_lblk, map->m_len, |
| flags, allocated); |
| ext4_ext_show_leaf(inode, path); |
| |
| /* |
| * When writing into unwritten space, we should not fail to |
| * allocate metadata blocks for the new extent block if needed. |
| */ |
| flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL; |
| |
| trace_ext4_ext_handle_unwritten_extents(inode, map, flags, |
| allocated, newblock); |
| |
| /* get_block() before submit the IO, split the extent */ |
| if (flags & EXT4_GET_BLOCKS_PRE_IO) { |
| ret = ext4_split_convert_extents(handle, inode, map, ppath, |
| flags | EXT4_GET_BLOCKS_CONVERT); |
| if (ret <= 0) |
| goto out; |
| map->m_flags |= EXT4_MAP_UNWRITTEN; |
| goto out; |
| } |
| /* IO end_io complete, convert the filled extent to written */ |
| if (flags & EXT4_GET_BLOCKS_CONVERT) { |
| if (flags & EXT4_GET_BLOCKS_ZERO) { |
| if (allocated > map->m_len) |
| allocated = map->m_len; |
| err = ext4_issue_zeroout(inode, map->m_lblk, newblock, |
| allocated); |
| if (err < 0) |
| goto out2; |
| } |
| ret = ext4_convert_unwritten_extents_endio(handle, inode, map, |
| ppath); |
| if (ret >= 0) { |
| ext4_update_inode_fsync_trans(handle, inode, 1); |
| err = check_eofblocks_fl(handle, inode, map->m_lblk, |
| path, map->m_len); |
| } else |
| err = ret; |
| map->m_flags |= EXT4_MAP_MAPPED; |
| map->m_pblk = newblock; |
| if (allocated > map->m_len) |
| allocated = map->m_len; |
| map->m_len = allocated; |
| goto out2; |
| } |
| /* buffered IO case */ |
| /* |
| * repeat fallocate creation request |
| * we already have an unwritten extent |
| */ |
| if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) { |
| map->m_flags |= EXT4_MAP_UNWRITTEN; |
| goto map_out; |
| } |
| |
| /* buffered READ or buffered write_begin() lookup */ |
| if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { |
| /* |
| * We have blocks reserved already. We |
| * return allocated blocks so that delalloc |
| * won't do block reservation for us. But |
| * the buffer head will be unmapped so that |
| * a read from the block returns 0s. |
| */ |
| map->m_flags |= EXT4_MAP_UNWRITTEN; |
| goto out1; |
| } |
| |
| /* buffered write, writepage time, convert*/ |
| ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags); |
| if (ret >= 0) |
| ext4_update_inode_fsync_trans(handle, inode, 1); |
| out: |
| if (ret <= 0) { |
| err = ret; |
| goto out2; |
| } else |
| allocated = ret; |
| map->m_flags |= EXT4_MAP_NEW; |
| /* |
| * if we allocated more blocks than requested |
| * we need to make sure we unmap the extra block |
| * allocated. The actual needed block will get |
| * unmapped later when we find the buffer_head marked |
| * new. |
| */ |
| if (allocated > map->m_len) { |
| unmap_underlying_metadata_blocks(inode->i_sb->s_bdev, |
| newblock + map->m_len, |
| allocated - map->m_len); |
| allocated = map->m_len; |
| } |
| map->m_len = allocated; |
| |
| /* |
| * If we have done fallocate with the offset that is already |
| * delayed allocated, we would have block reservation |
| * and quota reservation done in the delayed write path. |
| * But fallocate would have already updated quota and block |
| * count for this offset. So cancel these reservation |
| */ |
| if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { |
| unsigned int reserved_clusters; |
| reserved_clusters = get_reserved_cluster_alloc(inode, |
| map->m_lblk, map->m_len); |
| if (reserved_clusters) |
| ext4_da_update_reserve_space(inode, |
| reserved_clusters, |
| 0); |
| } |
| |
| map_out: |
| map->m_flags |= EXT4_MAP_MAPPED; |
| if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) { |
| err = check_eofblocks_fl(handle, inode, map->m_lblk, path, |
| map->m_len); |
| if (err < 0) |
| goto out2; |
| } |
| out1: |
| if (allocated > map->m_len) |
| allocated = map->m_len; |
| ext4_ext_show_leaf(inode, path); |
| map->m_pblk = newblock; |
| map->m_len = allocated; |
| out2: |
| return err ? err : allocated; |
| } |
| |
| /* |
| * get_implied_cluster_alloc - check to see if the requested |
| * allocation (in the map structure) overlaps with a cluster already |
| * allocated in an extent. |
| * @sb The filesystem superblock structure |
| * @map The requested lblk->pblk mapping |
| * @ex The extent structure which might contain an implied |
| * cluster allocation |
| * |
| * This function is called by ext4_ext_map_blocks() after we failed to |
| * find blocks that were already in the inode's extent tree. Hence, |
| * we know that the beginning of the requested region cannot overlap |
| * the extent from the inode's extent tree. There are three cases we |
| * want to catch. The first is this case: |
| * |
| * |--- cluster # N--| |
| * |--- extent ---| |---- requested region ---| |
| * |==========| |
| * |
| * The second case that we need to test for is this one: |
| * |
| * |--------- cluster # N ----------------| |
| * |--- requested region --| |------- extent ----| |
| * |=======================| |
| * |
| * The third case is when the requested region lies between two extents |
| * within the same cluster: |
| * |------------- cluster # N-------------| |
| * |----- ex -----| |---- ex_right ----| |
| * |------ requested region ------| |
| * |================| |
| * |
| * In each of the above cases, we need to set the map->m_pblk and |
| * map->m_len so it corresponds to the return the extent labelled as |
| * "|====|" from cluster #N, since it is already in use for data in |
| * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to |
| * signal to ext4_ext_map_blocks() that map->m_pblk should be treated |
| * as a new "allocated" block region. Otherwise, we will return 0 and |
| * ext4_ext_map_blocks() will then allocate one or more new clusters |
| * by calling ext4_mb_new_blocks(). |
| */ |
| static int get_implied_cluster_alloc(struct super_block *sb, |
| struct ext4_map_blocks *map, |
| struct ext4_extent *ex, |
| struct ext4_ext_path *path) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk); |
| ext4_lblk_t ex_cluster_start, ex_cluster_end; |
| ext4_lblk_t rr_cluster_start; |
| ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); |
| ext4_fsblk_t ee_start = ext4_ext_pblock(ex); |
| unsigned short ee_len = ext4_ext_get_actual_len(ex); |
| |
| /* The extent passed in that we are trying to match */ |
| ex_cluster_start = EXT4_B2C(sbi, ee_block); |
| ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1); |
| |
| /* The requested region passed into ext4_map_blocks() */ |
| rr_cluster_start = EXT4_B2C(sbi, map->m_lblk); |
| |
| if ((rr_cluster_start == ex_cluster_end) || |
| (rr_cluster_start == ex_cluster_start)) { |
| if (rr_cluster_start == ex_cluster_end) |
| ee_start += ee_len - 1; |
| map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset; |
| map->m_len = min(map->m_len, |
| (unsigned) sbi->s_cluster_ratio - c_offset); |
| /* |
| * Check for and handle this case: |
| * |
| * |--------- cluster # N-------------| |
| * |------- extent ----| |
| * |--- requested region ---| |
| * |===========| |
| */ |
| |
| if (map->m_lblk < ee_block) |
| map->m_len = min(map->m_len, ee_block - map->m_lblk); |
| |
| /* |
| * Check for the case where there is already another allocated |
| * block to the right of 'ex' but before the end of the cluster. |
| * |
| * |------------- cluster # N-------------| |
| * |----- ex -----| |---- ex_right ----| |
| * |------ requested region ------| |
| * |================| |
| */ |
| if (map->m_lblk > ee_block) { |
| ext4_lblk_t next = ext4_ext_next_allocated_block(path); |
| map->m_len = min(map->m_len, next - map->m_lblk); |
| } |
| |
| trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1); |
| return 1; |
| } |
| |
| trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0); |
| return 0; |
| } |
| |
| |
| /* |
| * Block allocation/map/preallocation routine for extents based files |
| * |
| * |
| * Need to be called with |
| * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block |
| * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) |
| * |
| * return > 0, number of of blocks already mapped/allocated |
| * if create == 0 and these are pre-allocated blocks |
| * buffer head is unmapped |
| * otherwise blocks are mapped |
| * |
| * return = 0, if plain look up failed (blocks have not been allocated) |
| * buffer head is unmapped |
| * |
| * return < 0, error case. |
| */ |
| int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, |
| struct ext4_map_blocks *map, int flags) |
| { |
| struct ext4_ext_path *path = NULL; |
| struct ext4_extent newex, *ex, *ex2; |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| ext4_fsblk_t newblock = 0; |
| int free_on_err = 0, err = 0, depth, ret; |
| unsigned int allocated = 0, offset = 0; |
| unsigned int allocated_clusters = 0; |
| struct ext4_allocation_request ar; |
| ext4_lblk_t cluster_offset; |
| bool map_from_cluster = false; |
| |
| ext_debug("blocks %u/%u requested for inode %lu\n", |
| map->m_lblk, map->m_len, inode->i_ino); |
| trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); |
| |
| /* find extent for this block */ |
| path = ext4_find_extent(inode, map->m_lblk, NULL, 0); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| path = NULL; |
| goto out2; |
| } |
| |
| depth = ext_depth(inode); |
| |
| /* |
| * consistent leaf must not be empty; |
| * this situation is possible, though, _during_ tree modification; |
| * this is why assert can't be put in ext4_find_extent() |
| */ |
| if (unlikely(path[depth].p_ext == NULL && depth != 0)) { |
| EXT4_ERROR_INODE(inode, "bad extent address " |
| "lblock: %lu, depth: %d pblock %lld", |
| (unsigned long) map->m_lblk, depth, |
| path[depth].p_block); |
| err = -EFSCORRUPTED; |
| goto out2; |
| } |
| |
| ex = path[depth].p_ext; |
| if (ex) { |
| ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); |
| ext4_fsblk_t ee_start = ext4_ext_pblock(ex); |
| unsigned short ee_len; |
| |
| |
| /* |
| * unwritten extents are treated as holes, except that |
| * we split out initialized portions during a write. |
| */ |
| ee_len = ext4_ext_get_actual_len(ex); |
| |
| trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len); |
| |
| /* if found extent covers block, simply return it */ |
| if (in_range(map->m_lblk, ee_block, ee_len)) { |
| newblock = map->m_lblk - ee_block + ee_start; |
| /* number of remaining blocks in the extent */ |
| allocated = ee_len - (map->m_lblk - ee_block); |
| ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk, |
| ee_block, ee_len, newblock); |
| |
| /* |
| * If the extent is initialized check whether the |
| * caller wants to convert it to unwritten. |
| */ |
| if ((!ext4_ext_is_unwritten(ex)) && |
| (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) { |
| allocated = convert_initialized_extent( |
| handle, inode, map, &path, |
| allocated); |
| goto out2; |
| } else if (!ext4_ext_is_unwritten(ex)) |
| goto out; |
| |
| ret = ext4_ext_handle_unwritten_extents( |
| handle, inode, map, &path, flags, |
| allocated, newblock); |
| if (ret < 0) |
| err = ret; |
| else |
| allocated = ret; |
| goto out2; |
| } |
| } |
| |
| /* |
| * requested block isn't allocated yet; |
| * we couldn't try to create block if create flag is zero |
| */ |
| if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { |
| ext4_lblk_t hole_start, hole_len; |
| |
| hole_start = map->m_lblk; |
| hole_len = ext4_ext_determine_hole(inode, path, &hole_start); |
| /* |
| * put just found gap into cache to speed up |
| * subsequent requests |
| */ |
| ext4_ext_put_gap_in_cache(inode, hole_start, hole_len); |
| |
| /* Update hole_len to reflect hole size after map->m_lblk */ |
| if (hole_start != map->m_lblk) |
| hole_len -= map->m_lblk - hole_start; |
| map->m_pblk = 0; |
| map->m_len = min_t(unsigned int, map->m_len, hole_len); |
| |
| goto out2; |
| } |
| |
| /* |
| * Okay, we need to do block allocation. |
| */ |
| newex.ee_block = cpu_to_le32(map->m_lblk); |
| cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk); |
| |
| /* |
| * If we are doing bigalloc, check to see if the extent returned |
| * by ext4_find_extent() implies a cluster we can use. |
| */ |
| if (cluster_offset && ex && |
| get_implied_cluster_alloc(inode->i_sb, map, ex, path)) { |
| ar.len = allocated = map->m_len; |
| newblock = map->m_pblk; |
| map_from_cluster = true; |
| goto got_allocated_blocks; |
| } |
| |
| /* find neighbour allocated blocks */ |
| ar.lleft = map->m_lblk; |
| err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); |
| if (err) |
| goto out2; |
| ar.lright = map->m_lblk; |
| ex2 = NULL; |
| err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2); |
| if (err) |
| goto out2; |
| |
| /* Check if the extent after searching to the right implies a |
| * cluster we can use. */ |
| if ((sbi->s_cluster_ratio > 1) && ex2 && |
| get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) { |
| ar.len = allocated = map->m_len; |
| newblock = map->m_pblk; |
| map_from_cluster = true; |
| goto got_allocated_blocks; |
| } |
| |
| /* |
| * See if request is beyond maximum number of blocks we can have in |
| * a single extent. For an initialized extent this limit is |
| * EXT_INIT_MAX_LEN and for an unwritten extent this limit is |
| * EXT_UNWRITTEN_MAX_LEN. |
| */ |
| if (map->m_len > EXT_INIT_MAX_LEN && |
| !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT)) |
| map->m_len = EXT_INIT_MAX_LEN; |
| else if (map->m_len > EXT_UNWRITTEN_MAX_LEN && |
| (flags & EXT4_GET_BLOCKS_UNWRIT_EXT)) |
| map->m_len = EXT_UNWRITTEN_MAX_LEN; |
| |
| /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */ |
| newex.ee_len = cpu_to_le16(map->m_len); |
| err = ext4_ext_check_overlap(sbi, inode, &newex, path); |
| if (err) |
| allocated = ext4_ext_get_actual_len(&newex); |
| else |
| allocated = map->m_len; |
| |
| /* allocate new block */ |
| ar.inode = inode; |
| ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk); |
| ar.logical = map->m_lblk; |
| /* |
| * We calculate the offset from the beginning of the cluster |
| * for the logical block number, since when we allocate a |
| * physical cluster, the physical block should start at the |
| * same offset from the beginning of the cluster. This is |
| * needed so that future calls to get_implied_cluster_alloc() |
| * work correctly. |
| */ |
| offset = EXT4_LBLK_COFF(sbi, map->m_lblk); |
| ar.len = EXT4_NUM_B2C(sbi, offset+allocated); |
| ar.goal -= offset; |
| ar.logical -= offset; |
| if (S_ISREG(inode->i_mode)) |
| ar.flags = EXT4_MB_HINT_DATA; |
| else |
| /* disable in-core preallocation for non-regular files */ |
| ar.flags = 0; |
| if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE) |
| ar.flags |= EXT4_MB_HINT_NOPREALLOC; |
| if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) |
| ar.flags |= EXT4_MB_DELALLOC_RESERVED; |
| if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL) |
| ar.flags |= EXT4_MB_USE_RESERVED; |
| newblock = ext4_mb_new_blocks(handle, &ar, &err); |
| if (!newblock) |
| goto out2; |
| ext_debug("allocate new block: goal %llu, found %llu/%u\n", |
| ar.goal, newblock, allocated); |
| free_on_err = 1; |
| allocated_clusters = ar.len; |
| ar.len = EXT4_C2B(sbi, ar.len) - offset; |
| if (ar.len > allocated) |
| ar.len = allocated; |
| |
| got_allocated_blocks: |
| /* try to insert new extent into found leaf and return */ |
| ext4_ext_store_pblock(&newex, newblock + offset); |
| newex.ee_len = cpu_to_le16(ar.len); |
| /* Mark unwritten */ |
| if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){ |
| ext4_ext_mark_unwritten(&newex); |
| map->m_flags |= EXT4_MAP_UNWRITTEN; |
| } |
| |
| err = 0; |
| if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) |
| err = check_eofblocks_fl(handle, inode, map->m_lblk, |
| path, ar.len); |
| if (!err) |
| err = ext4_ext_insert_extent(handle, inode, &path, |
| &newex, flags); |
| |
| if (err && free_on_err) { |
| int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ? |
| EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0; |
| /* free data blocks we just allocated */ |
| /* not a good idea to call discard here directly, |
| * but otherwise we'd need to call it every free() */ |
| ext4_discard_preallocations(inode); |
| ext4_free_blocks(handle, inode, NULL, newblock, |
| EXT4_C2B(sbi, allocated_clusters), fb_flags); |
| goto out2; |
| } |
| |
| /* previous routine could use block we allocated */ |
| newblock = ext4_ext_pblock(&newex); |
| allocated = ext4_ext_get_actual_len(&newex); |
| if (allocated > map->m_len) |
| allocated = map->m_len; |
| map->m_flags |= EXT4_MAP_NEW; |
| |
| /* |
| * Update reserved blocks/metadata blocks after successful |
| * block allocation which had been deferred till now. |
| */ |
| if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { |
| unsigned int reserved_clusters; |
| /* |
| * Check how many clusters we had reserved this allocated range |
| */ |
| reserved_clusters = get_reserved_cluster_alloc(inode, |
| map->m_lblk, allocated); |
| if (!map_from_cluster) { |
| BUG_ON(allocated_clusters < reserved_clusters); |
| if (reserved_clusters < allocated_clusters) { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| int reservation = allocated_clusters - |
| reserved_clusters; |
| /* |
| * It seems we claimed few clusters outside of |
| * the range of this allocation. We should give |
| * it back to the reservation pool. This can |
| * happen in the following case: |
| * |
| * * Suppose s_cluster_ratio is 4 (i.e., each |
| * cluster has 4 blocks. Thus, the clusters |
| * are [0-3],[4-7],[8-11]... |
| * * First comes delayed allocation write for |
| * logical blocks 10 & 11. Since there were no |
| * previous delayed allocated blocks in the |
| * range [8-11], we would reserve 1 cluster |
| * for this write. |
| * * Next comes write for logical blocks 3 to 8. |
| * In this case, we will reserve 2 clusters |
| * (for [0-3] and [4-7]; and not for [8-11] as |
| * that range has a delayed allocated blocks. |
| * Thus total reserved clusters now becomes 3. |
| * * Now, during the delayed allocation writeout |
| * time, we will first write blocks [3-8] and |
| * allocate 3 clusters for writing these |
| * blocks. Also, we would claim all these |
| * three clusters above. |
| * * Now when we come here to writeout the |
| * blocks [10-11], we would expect to claim |
| * the reservation of 1 cluster we had made |
| * (and we would claim it since there are no |
| * more delayed allocated blocks in the range |
| * [8-11]. But our reserved cluster count had |
| * already gone to 0. |
| * |
| * Thus, at the step 4 above when we determine |
| * that there are still some unwritten delayed |
| * allocated blocks outside of our current |
| * block range, we should increment the |
| * reserved clusters count so that when the |
| * remaining blocks finally gets written, we |
| * could claim them. |
| */ |
| dquot_reserve_block(inode, |
| EXT4_C2B(sbi, reservation)); |
| spin_lock(&ei->i_block_reservation_lock); |
| ei->i_reserved_data_blocks += reservation; |
| spin_unlock(&ei->i_block_reservation_lock); |
| } |
| /* |
| * We will claim quota for all newly allocated blocks. |
| * We're updating the reserved space *after* the |
| * correction above so we do not accidentally free |
| * all the metadata reservation because we might |
| * actually need it later on. |
| */ |
| ext4_da_update_reserve_space(inode, allocated_clusters, |
| 1); |
| } |
| } |
| |
| /* |
| * Cache the extent and update transaction to commit on fdatasync only |
| * when it is _not_ an unwritten extent. |
| */ |
| if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0) |
| ext4_update_inode_fsync_trans(handle, inode, 1); |
| else |
| ext4_update_inode_fsync_trans(handle, inode, 0); |
| out: |
| if (allocated > map->m_len) |
| allocated = map->m_len; |
| ext4_ext_show_leaf(inode, path); |
| map->m_flags |= EXT4_MAP_MAPPED; |
| map->m_pblk = newblock; |
| map->m_len = allocated; |
| out2: |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| |
| trace_ext4_ext_map_blocks_exit(inode, flags, map, |
| err ? err : allocated); |
| return err ? err : allocated; |
| } |
| |
| void ext4_ext_truncate(handle_t *handle, struct inode *inode) |
| { |
| struct super_block *sb = inode->i_sb; |
| ext4_lblk_t last_block; |
| int err = 0; |
| |
| /* |
| * TODO: optimization is possible here. |
| * Probably we need not scan at all, |
| * because page truncation is enough. |
| */ |
| |
| /* we have to know where to truncate from in crash case */ |
| EXT4_I(inode)->i_disksize = inode->i_size; |
| ext4_mark_inode_dirty(handle, inode); |
| |
| last_block = (inode->i_size + sb->s_blocksize - 1) |
| >> EXT4_BLOCK_SIZE_BITS(sb); |
| retry: |
| err = ext4_es_remove_extent(inode, last_block, |
| EXT_MAX_BLOCKS - last_block); |
| if (err == -ENOMEM) { |
| cond_resched(); |
| congestion_wait(BLK_RW_ASYNC, HZ/50); |
| goto retry; |
| } |
| if (err) { |
| ext4_std_error(inode->i_sb, err); |
| return; |
| } |
| err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1); |
| ext4_std_error(inode->i_sb, err); |
| } |
| |
| static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset, |
| ext4_lblk_t len, loff_t new_size, |
| int flags, int mode) |
| { |
| struct inode *inode = file_inode(file); |
| handle_t *handle; |
| int ret = 0; |
| int ret2 = 0; |
| int retries = 0; |
| int depth = 0; |
| struct ext4_map_blocks map; |
| unsigned int credits; |
| loff_t epos; |
| |
| BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)); |
| map.m_lblk = offset; |
| map.m_len = len; |
| /* |
| * Don't normalize the request if it can fit in one extent so |
| * that it doesn't get unnecessarily split into multiple |
| * extents. |
| */ |
| if (len <= EXT_UNWRITTEN_MAX_LEN) |
| flags |= EXT4_GET_BLOCKS_NO_NORMALIZE; |
| |
| /* |
| * credits to insert 1 extent into extent tree |
| */ |
| credits = ext4_chunk_trans_blocks(inode, len); |
| depth = ext_depth(inode); |
| |
| retry: |
| while (ret >= 0 && len) { |
| /* |
| * Recalculate credits when extent tree depth changes. |
| */ |
| if (depth >= 0 && depth != ext_depth(inode)) { |
| credits = ext4_chunk_trans_blocks(inode, len); |
| depth = ext_depth(inode); |
| } |
| |
| handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, |
| credits); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| break; |
| } |
| ret = ext4_map_blocks(handle, inode, &map, flags); |
| if (ret <= 0) { |
| ext4_debug("inode #%lu: block %u: len %u: " |
| "ext4_ext_map_blocks returned %d", |
| inode->i_ino, map.m_lblk, |
| map.m_len, ret); |
| ext4_mark_inode_dirty(handle, inode); |
| ret2 = ext4_journal_stop(handle); |
| break; |
| } |
| map.m_lblk += ret; |
| map.m_len = len = len - ret; |
| epos = (loff_t)map.m_lblk << inode->i_blkbits; |
| inode->i_ctime = ext4_current_time(inode); |
| if (new_size) { |
| if (epos > new_size) |
| epos = new_size; |
| if (ext4_update_inode_size(inode, epos) & 0x1) |
| inode->i_mtime = inode->i_ctime; |
| } else { |
| if (epos > inode->i_size) |
| ext4_set_inode_flag(inode, |
| EXT4_INODE_EOFBLOCKS); |
| } |
| ext4_mark_inode_dirty(handle, inode); |
| ext4_update_inode_fsync_trans(handle, inode, 1); |
| ret2 = ext4_journal_stop(handle); |
| if (ret2) |
| break; |
| } |
| if (ret == -ENOSPC && |
| ext4_should_retry_alloc(inode->i_sb, &retries)) { |
| ret = 0; |
| goto retry; |
| } |
| |
| return ret > 0 ? ret2 : ret; |
| } |
| |
| static long ext4_zero_range(struct file *file, loff_t offset, |
| loff_t len, int mode) |
| { |
| struct inode *inode = file_inode(file); |
| handle_t *handle = NULL; |
| unsigned int max_blocks; |
| loff_t new_size = 0; |
| int ret = 0; |
| int flags; |
| int credits; |
| int partial_begin, partial_end; |
| loff_t start, end; |
| ext4_lblk_t lblk; |
| unsigned int blkbits = inode->i_blkbits; |
| |
| trace_ext4_zero_range(inode, offset, len, mode); |
| |
| if (!S_ISREG(inode->i_mode)) |
| return -EINVAL; |
| |
| /* Call ext4_force_commit to flush all data in case of data=journal. */ |
| if (ext4_should_journal_data(inode)) { |
| ret = ext4_force_commit(inode->i_sb); |
| if (ret) |
| return ret; |
| } |
| |
| /* |
| * Round up offset. This is not fallocate, we neet to zero out |
| * blocks, so convert interior block aligned part of the range to |
| * unwritten and possibly manually zero out unaligned parts of the |
| * range. |
| */ |
| start = round_up(offset, 1 << blkbits); |
| end = round_down((offset + len), 1 << blkbits); |
| |
| if (start < offset || end > offset + len) |
| return -EINVAL; |
| partial_begin = offset & ((1 << blkbits) - 1); |
| partial_end = (offset + len) & ((1 << blkbits) - 1); |
| |
| lblk = start >> blkbits; |
| max_blocks = (end >> blkbits); |
| if (max_blocks < lblk) |
| max_blocks = 0; |
| else |
| max_blocks -= lblk; |
| |
| inode_lock(inode); |
| |
| /* |
| * Indirect files do not support unwritten extnets |
| */ |
| if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { |
| ret = -EOPNOTSUPP; |
| goto out_mutex; |
| } |
| |
| if (!(mode & FALLOC_FL_KEEP_SIZE) && |
| (offset + len > i_size_read(inode) || |
| offset + len > EXT4_I(inode)->i_disksize)) { |
| new_size = offset + len; |
| ret = inode_newsize_ok(inode, new_size); |
| if (ret) |
| goto out_mutex; |
| } |
| |
| flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT; |
| if (mode & FALLOC_FL_KEEP_SIZE) |
| flags |= EXT4_GET_BLOCKS_KEEP_SIZE; |
| |
| /* Wait all existing dio workers, newcomers will block on i_mutex */ |
| ext4_inode_block_unlocked_dio(inode); |
| inode_dio_wait(inode); |
| |
| /* Preallocate the range including the unaligned edges */ |
| if (partial_begin || partial_end) { |
| ret = ext4_alloc_file_blocks(file, |
| round_down(offset, 1 << blkbits) >> blkbits, |
| (round_up((offset + len), 1 << blkbits) - |
| round_down(offset, 1 << blkbits)) >> blkbits, |
| new_size, flags, mode); |
| if (ret) |
| goto out_dio; |
| |
| } |
| |
| /* Zero range excluding the unaligned edges */ |
| if (max_blocks > 0) { |
| flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN | |
| EXT4_EX_NOCACHE); |
| |
| /* |
| * Prevent page faults from reinstantiating pages we have |
| * released from page cache. |
| */ |
| down_write(&EXT4_I(inode)->i_mmap_sem); |
| ret = ext4_update_disksize_before_punch(inode, offset, len); |
| if (ret) { |
| up_write(&EXT4_I(inode)->i_mmap_sem); |
| goto out_dio; |
| } |
| /* Now release the pages and zero block aligned part of pages */ |
| truncate_pagecache_range(inode, start, end - 1); |
| inode->i_mtime = inode->i_ctime = ext4_current_time(inode); |
| |
| ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, |
| flags, mode); |
| up_write(&EXT4_I(inode)->i_mmap_sem); |
| if (ret) |
| goto out_dio; |
| } |
| if (!partial_begin && !partial_end) |
| goto out_dio; |
| |
| /* |
| * In worst case we have to writeout two nonadjacent unwritten |
| * blocks and update the inode |
| */ |
| credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1; |
| if (ext4_should_journal_data(inode)) |
| credits += 2; |
| handle = ext4_journal_start(inode, EXT4_HT_MISC, credits); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| ext4_std_error(inode->i_sb, ret); |
| goto out_dio; |
| } |
| |
| inode->i_mtime = inode->i_ctime = ext4_current_time(inode); |
| if (new_size) { |
| ext4_update_inode_size(inode, new_size); |
| } else { |
| /* |
| * Mark that we allocate beyond EOF so the subsequent truncate |
| * can proceed even if the new size is the same as i_size. |
| */ |
| if ((offset + len) > i_size_read(inode)) |
| ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS); |
| } |
| ext4_mark_inode_dirty(handle, inode); |
| |
| /* Zero out partial block at the edges of the range */ |
| ret = ext4_zero_partial_blocks(handle, inode, offset, len); |
| if (ret >= 0) |
| ext4_update_inode_fsync_trans(handle, inode, 1); |
| |
| if (file->f_flags & O_SYNC) |
| ext4_handle_sync(handle); |
| |
| ext4_journal_stop(handle); |
| out_dio: |
| ext4_inode_resume_unlocked_dio(inode); |
| out_mutex: |
| inode_unlock(inode); |
| return ret; |
| } |
| |
| /* |
| * preallocate space for a file. This implements ext4's fallocate file |
| * operation, which gets called from sys_fallocate system call. |
| * For block-mapped files, posix_fallocate should fall back to the method |
| * of writing zeroes to the required new blocks (the same behavior which is |
| * expected for file systems which do not support fallocate() system call). |
| */ |
| long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
| { |
| struct inode *inode = file_inode(file); |
| loff_t new_size = 0; |
| unsigned int max_blocks; |
| int ret = 0; |
| int flags; |
| ext4_lblk_t lblk; |
| unsigned int blkbits = inode->i_blkbits; |
| |
| /* |
| * Encrypted inodes can't handle collapse range or insert |
| * range since we would need to re-encrypt blocks with a |
| * different IV or XTS tweak (which are based on the logical |
| * block number). |
| * |
| * XXX It's not clear why zero range isn't working, but we'll |
| * leave it disabled for encrypted inodes for now. This is a |
| * bug we should fix.... |
| */ |
| if (ext4_encrypted_inode(inode) && |
| (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE | |
| FALLOC_FL_ZERO_RANGE))) |
| return -EOPNOTSUPP; |
| |
| /* Return error if mode is not supported */ |
| if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | |
| FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | |
| FALLOC_FL_INSERT_RANGE)) |
| return -EOPNOTSUPP; |
| |
| if (mode & FALLOC_FL_PUNCH_HOLE) |
| return ext4_punch_hole(inode, offset, len); |
| |
| ret = ext4_convert_inline_data(inode); |
| if (ret) |
| return ret; |
| |
| if (mode & FALLOC_FL_COLLAPSE_RANGE) |
| return ext4_collapse_range(inode, offset, len); |
| |
| if (mode & FALLOC_FL_INSERT_RANGE) |
| return ext4_insert_range(inode, offset, len); |
| |
| if (mode & FALLOC_FL_ZERO_RANGE) |
| return ext4_zero_range(file, offset, len, mode); |
| |
| trace_ext4_fallocate_enter(inode, offset, len, mode); |
| lblk = offset >> blkbits; |
| |
| max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits); |
| flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT; |
| if (mode & FALLOC_FL_KEEP_SIZE) |
| flags |= EXT4_GET_BLOCKS_KEEP_SIZE; |
| |
| inode_lock(inode); |
| |
| /* |
| * We only support preallocation for extent-based files only |
| */ |
| if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { |
| ret = -EOPNOTSUPP; |
| goto out; |
| } |
| |
| if (!(mode & FALLOC_FL_KEEP_SIZE) && |
| (offset + len > i_size_read(inode) || |
| offset + len > EXT4_I(inode)->i_disksize)) { |
| new_size = offset + len; |
| ret = inode_newsize_ok(inode, new_size); |
| if (ret) |
| goto out; |
| } |
| |
| /* Wait all existing dio workers, newcomers will block on i_mutex */ |
| ext4_inode_block_unlocked_dio(inode); |
| inode_dio_wait(inode); |
| |
| ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, |
| flags, mode); |
| ext4_inode_resume_unlocked_dio(inode); |
| if (ret) |
| goto out; |
| |
| if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) { |
| ret = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal, |
| EXT4_I(inode)->i_sync_tid); |
| } |
| out: |
| inode_unlock(inode); |
| trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); |
| return ret; |
| } |
| |
| /* |
| * This function convert a range of blocks to written extents |
| * The caller of this function will pass the start offset and the size. |
| * all unwritten extents within this range will be converted to |
| * written extents. |
| * |
| * This function is called from the direct IO end io call back |
| * function, to convert the fallocated extents after IO is completed. |
| * Returns 0 on success. |
| */ |
| int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode, |
| loff_t offset, ssize_t len) |
| { |
| unsigned int max_blocks; |
| int ret = 0; |
| int ret2 = 0; |
| struct ext4_map_blocks map; |
| unsigned int credits, blkbits = inode->i_blkbits; |
| |
| map.m_lblk = offset >> blkbits; |
| max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits); |
| |
| /* |
| * This is somewhat ugly but the idea is clear: When transaction is |
| * reserved, everything goes into it. Otherwise we rather start several |
| * smaller transactions for conversion of each extent separately. |
| */ |
| if (handle) { |
| handle = ext4_journal_start_reserved(handle, |
| EXT4_HT_EXT_CONVERT); |
| if (IS_ERR(handle)) |
| return PTR_ERR(handle); |
| credits = 0; |
| } else { |
| /* |
| * credits to insert 1 extent into extent tree |
| */ |
| credits = ext4_chunk_trans_blocks(inode, max_blocks); |
| } |
| while (ret >= 0 && ret < max_blocks) { |
| map.m_lblk += ret; |
| map.m_len = (max_blocks -= ret); |
| if (credits) { |
| handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, |
| credits); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| break; |
| } |
| } |
| ret = ext4_map_blocks(handle, inode, &map, |
| EXT4_GET_BLOCKS_IO_CONVERT_EXT); |
| if (ret <= 0) |
| ext4_warning(inode->i_sb, |
| "inode #%lu: block %u: len %u: " |
| "ext4_ext_map_blocks returned %d", |
| inode->i_ino, map.m_lblk, |
| map.m_len, ret); |
| ext4_mark_inode_dirty(handle, inode); |
| if (credits) |
| ret2 = ext4_journal_stop(handle); |
| if (ret <= 0 || ret2) |
| break; |
| } |
| if (!credits) |
| ret2 = ext4_journal_stop(handle); |
| return ret > 0 ? ret2 : ret; |
| } |
| |
| /* |
| * If newes is not existing extent (newes->ec_pblk equals zero) find |
| * delayed extent at start of newes and update newes accordingly and |
| * return start of the next delayed extent. |
| * |
| * If newes is existing extent (newes->ec_pblk is not equal zero) |
| * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed |
| * extent found. Leave newes unmodified. |
| */ |
| static int ext4_find_delayed_extent(struct inode *inode, |
| struct extent_status *newes) |
| { |
| struct extent_status es; |
| ext4_lblk_t block, next_del; |
| |
| if (newes->es_pblk == 0) { |
| ext4_es_find_delayed_extent_range(inode, newes->es_lblk, |
| newes->es_lblk + newes->es_len - 1, &es); |
| |
| /* |
| * No extent in extent-tree contains block @newes->es_pblk, |
| * then the block may stay in 1)a hole or 2)delayed-extent. |
| */ |
| if (es.es_len == 0) |
| /* A hole found. */ |
| return 0; |
| |
| if (es.es_lblk > newes->es_lblk) { |
| /* A hole found. */ |
| newes->es_len = min(es.es_lblk - newes->es_lblk, |
| newes->es_len); |
| return 0; |
| } |
| |
| newes->es_len = es.es_lblk + es.es_len - newes->es_lblk; |
| } |
| |
| block = newes->es_lblk + newes->es_len; |
| ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es); |
| if (es.es_len == 0) |
| next_del = EXT_MAX_BLOCKS; |
| else |
| next_del = es.es_lblk; |
| |
| return next_del; |
| } |
| /* fiemap flags we can handle specified here */ |
| #define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR) |
| |
| static int ext4_xattr_fiemap(struct inode *inode, |
| struct fiemap_extent_info *fieinfo) |
| { |
| __u64 physical = 0; |
| __u64 length; |
| __u32 flags = FIEMAP_EXTENT_LAST; |
| int blockbits = inode->i_sb->s_blocksize_bits; |
| int error = 0; |
| |
| /* in-inode? */ |
| if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { |
| struct ext4_iloc iloc; |
| int offset; /* offset of xattr in inode */ |
| |
| error = ext4_get_inode_loc(inode, &iloc); |
| if (error) |
| return error; |
| physical = (__u64)iloc.bh->b_blocknr << blockbits; |
| offset = EXT4_GOOD_OLD_INODE_SIZE + |
| EXT4_I(inode)->i_extra_isize; |
| physical += offset; |
| length = EXT4_SB(inode->i_sb)->s_inode_size - offset; |
| flags |= FIEMAP_EXTENT_DATA_INLINE; |
| brelse(iloc.bh); |
| } else { /* external block */ |
| physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits; |
| length = inode->i_sb->s_blocksize; |
| } |
| |
| if (physical) |
| error = fiemap_fill_next_extent(fieinfo, 0, physical, |
| length, flags); |
| return (error < 0 ? error : 0); |
| } |
| |
| int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, |
| __u64 start, __u64 len) |
| { |
| ext4_lblk_t start_blk; |
| int error = 0; |
| |
| if (ext4_has_inline_data(inode)) { |
| int has_inline = 1; |
| |
| error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline, |
| start, len); |
| |
| if (has_inline) |
| return error; |
| } |
| |
| if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) { |
| error = ext4_ext_precache(inode); |
| if (error) |
| return error; |
| } |
| |
| /* fallback to generic here if not in extents fmt */ |
| if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) |
| return generic_block_fiemap(inode, fieinfo, start, len, |
| ext4_get_block); |
| |
| if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS)) |
| return -EBADR; |
| |
| if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) { |
| error = ext4_xattr_fiemap(inode, fieinfo); |
| } else { |
| ext4_lblk_t len_blks; |
| __u64 last_blk; |
| |
| start_blk = start >> inode->i_sb->s_blocksize_bits; |
| last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits; |
| if (last_blk >= EXT_MAX_BLOCKS) |
| last_blk = EXT_MAX_BLOCKS-1; |
| len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1; |
| |
| /* |
| * Walk the extent tree gathering extent information |
| * and pushing extents back to the user. |
| */ |
| error = ext4_fill_fiemap_extents(inode, start_blk, |
| len_blks, fieinfo); |
| } |
| return error; |
| } |
| |
| /* |
| * ext4_access_path: |
| * Function to access the path buffer for marking it dirty. |
| * It also checks if there are sufficient credits left in the journal handle |
| * to update path. |
| */ |
| static int |
| ext4_access_path(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| int credits, err; |
| |
| if (!ext4_handle_valid(handle)) |
| return 0; |
| |
| /* |
| * Check if need to extend journal credits |
| * 3 for leaf, sb, and inode plus 2 (bmap and group |
| * descriptor) for each block group; assume two block |
| * groups |
| */ |
| if (handle->h_buffer_credits < 7) { |
| credits = ext4_writepage_trans_blocks(inode); |
| err = ext4_ext_truncate_extend_restart(handle, inode, credits); |
| /* EAGAIN is success */ |
| if (err && err != -EAGAIN) |
| return err; |
| } |
| |
| err = ext4_ext_get_access(handle, inode, path); |
| return err; |
| } |
| |
| /* |
| * ext4_ext_shift_path_extents: |
| * Shift the extents of a path structure lying between path[depth].p_ext |
| * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells |
| * if it is right shift or left shift operation. |
| */ |
| static int |
| ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift, |
| struct inode *inode, handle_t *handle, |
| enum SHIFT_DIRECTION SHIFT) |
| { |
| int depth, err = 0; |
| struct ext4_extent *ex_start, *ex_last; |
| bool update = 0; |
| depth = path->p_depth; |
| |
| while (depth >= 0) { |
| if (depth == path->p_depth) { |
| ex_start = path[depth].p_ext; |
| if (!ex_start) |
| return -EFSCORRUPTED; |
| |
| ex_last = EXT_LAST_EXTENT(path[depth].p_hdr); |
| |
| err = ext4_access_path(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) |
| update = 1; |
| |
| while (ex_start <= ex_last) { |
| if (SHIFT == SHIFT_LEFT) { |
| le32_add_cpu(&ex_start->ee_block, |
| -shift); |
| /* Try to merge to the left. */ |
| if ((ex_start > |
| EXT_FIRST_EXTENT(path[depth].p_hdr)) |
| && |
| ext4_ext_try_to_merge_right(inode, |
| path, ex_start - 1)) |
| ex_last--; |
| else |
| ex_start++; |
| } else { |
| le32_add_cpu(&ex_last->ee_block, shift); |
| ext4_ext_try_to_merge_right(inode, path, |
| ex_last); |
| ex_last--; |
| } |
| } |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| if (--depth < 0 || !update) |
| break; |
| } |
| |
| /* Update index too */ |
| err = ext4_access_path(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| if (SHIFT == SHIFT_LEFT) |
| le32_add_cpu(&path[depth].p_idx->ei_block, -shift); |
| else |
| le32_add_cpu(&path[depth].p_idx->ei_block, shift); |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| /* we are done if current index is not a starting index */ |
| if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr)) |
| break; |
| |
| depth--; |
| } |
| |
| out: |
| return err; |
| } |
| |
| /* |
| * ext4_ext_shift_extents: |
| * All the extents which lies in the range from @start to the last allocated |
| * block for the @inode are shifted either towards left or right (depending |
| * upon @SHIFT) by @shift blocks. |
| * On success, 0 is returned, error otherwise. |
| */ |
| static int |
| ext4_ext_shift_extents(struct inode *inode, handle_t *handle, |
| ext4_lblk_t start, ext4_lblk_t shift, |
| enum SHIFT_DIRECTION SHIFT) |
| { |
| struct ext4_ext_path *path; |
| int ret = 0, depth; |
| struct ext4_extent *extent; |
| ext4_lblk_t stop, *iterator, ex_start, ex_end; |
| |
| /* Let path point to the last extent */ |
| path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, |
| EXT4_EX_NOCACHE); |
| if (IS_ERR(path)) |
| return PTR_ERR(path); |
| |
| depth = path->p_depth; |
| extent = path[depth].p_ext; |
| if (!extent) |
| goto out; |
| |
| stop = le32_to_cpu(extent->ee_block); |
| |
| /* |
| * For left shifts, make sure the hole on the left is big enough to |
| * accommodate the shift. For right shifts, make sure the last extent |
| * won't be shifted beyond EXT_MAX_BLOCKS. |
| */ |
| if (SHIFT == SHIFT_LEFT) { |
| path = ext4_find_extent(inode, start - 1, &path, |
| EXT4_EX_NOCACHE); |
| if (IS_ERR(path)) |
| return PTR_ERR(path); |
| depth = path->p_depth; |
| extent = path[depth].p_ext; |
| if (extent) { |
| ex_start = le32_to_cpu(extent->ee_block); |
| ex_end = le32_to_cpu(extent->ee_block) + |
| ext4_ext_get_actual_len(extent); |
| } else { |
| ex_start = 0; |
| ex_end = 0; |
| } |
| |
| if ((start == ex_start && shift > ex_start) || |
| (shift > start - ex_end)) { |
| ret = -EINVAL; |
| goto out; |
| } |
| } else { |
| if (shift > EXT_MAX_BLOCKS - |
| (stop + ext4_ext_get_actual_len(extent))) { |
| ret = -EINVAL; |
| goto out; |
| } |
| } |
| |
| /* |
| * In case of left shift, iterator points to start and it is increased |
| * till we reach stop. In case of right shift, iterator points to stop |
| * and it is decreased till we reach start. |
| */ |
| if (SHIFT == SHIFT_LEFT) |
| iterator = &start; |
| else |
| iterator = &stop; |
| |
| /* |
| * Its safe to start updating extents. Start and stop are unsigned, so |
| * in case of right shift if extent with 0 block is reached, iterator |
| * becomes NULL to indicate the end of the loop. |
| */ |
| while (iterator && start <= stop) { |
| path = ext4_find_extent(inode, *iterator, &path, |
| EXT4_EX_NOCACHE); |
| if (IS_ERR(path)) |
| return PTR_ERR(path); |
| depth = path->p_depth; |
| extent = path[depth].p_ext; |
| if (!extent) { |
| EXT4_ERROR_INODE(inode, "unexpected hole at %lu", |
| (unsigned long) *iterator); |
| return -EFSCORRUPTED; |
| } |
| if (SHIFT == SHIFT_LEFT && *iterator > |
| le32_to_cpu(extent->ee_block)) { |
| /* Hole, move to the next extent */ |
| if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) { |
| path[depth].p_ext++; |
| } else { |
| *iterator = ext4_ext_next_allocated_block(path); |
| continue; |
| } |
| } |
| |
| if (SHIFT == SHIFT_LEFT) { |
| extent = EXT_LAST_EXTENT(path[depth].p_hdr); |
| *iterator = le32_to_cpu(extent->ee_block) + |
| ext4_ext_get_actual_len(extent); |
| } else { |
| extent = EXT_FIRST_EXTENT(path[depth].p_hdr); |
| if (le32_to_cpu(extent->ee_block) > 0) |
| *iterator = le32_to_cpu(extent->ee_block) - 1; |
| else |
| /* Beginning is reached, end of the loop */ |
| iterator = NULL; |
| /* Update path extent in case we need to stop */ |
| while (le32_to_cpu(extent->ee_block) < start) |
| extent++; |
| path[depth].p_ext = extent; |
| } |
| ret = ext4_ext_shift_path_extents(path, shift, inode, |
| handle, SHIFT); |
| if (ret) |
| break; |
| } |
| out: |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| return ret; |
| } |
| |
| /* |
| * ext4_collapse_range: |
| * This implements the fallocate's collapse range functionality for ext4 |
| * Returns: 0 and non-zero on error. |
| */ |
| int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) |
| { |
| struct super_block *sb = inode->i_sb; |
| ext4_lblk_t punch_start, punch_stop; |
| handle_t *handle; |
| unsigned int credits; |
| loff_t new_size, ioffset; |
| int ret; |
| |
| /* |
| * We need to test this early because xfstests assumes that a |
| * collapse range of (0, 1) will return EOPNOTSUPP if the file |
| * system does not support collapse range. |
| */ |
| if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) |
| return -EOPNOTSUPP; |
| |
| /* Collapse range works only on fs block size aligned offsets. */ |
| if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) || |
| len & (EXT4_CLUSTER_SIZE(sb) - 1)) |
| return -EINVAL; |
| |
| if (!S_ISREG(inode->i_mode)) |
| return -EINVAL; |
| |
| trace_ext4_collapse_range(inode, offset, len); |
| |
| punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb); |
| punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb); |
| |
| /* Call ext4_force_commit to flush all data in case of data=journal. */ |
| if (ext4_should_journal_data(inode)) { |
| ret = ext4_force_commit(inode->i_sb); |
| if (ret) |
| return ret; |
| } |
| |
| inode_lock(inode); |
| /* |
| * There is no need to overlap collapse range with EOF, in which case |
| * it is effectively a truncate operation |
| */ |
| if (offset + len >= i_size_read(inode)) { |
| ret = -EINVAL; |
| goto out_mutex; |
| } |
| |
| /* Currently just for extent based files */ |
| if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { |
| ret = -EOPNOTSUPP; |
| goto out_mutex; |
| } |
| |
| /* Wait for existing dio to complete */ |
| ext4_inode_block_unlocked_dio(inode); |
| inode_dio_wait(inode); |
| |
| /* |
| * Prevent page faults from reinstantiating pages we have released from |
| * page cache. |
| */ |
| down_write(&EXT4_I(inode)->i_mmap_sem); |
| /* |
| * Need to round down offset to be aligned with page size boundary |
| * for page size > block size. |
| */ |
| ioffset = round_down(offset, PAGE_SIZE); |
| /* |
| * Write tail of the last page before removed range since it will get |
| * removed from the page cache below. |
| */ |
| ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, offset); |
| if (ret) |
| goto out_mmap; |
| /* |
| * Write data that will be shifted to preserve them when discarding |
| * page cache below. We are also protected from pages becoming dirty |
| * by i_mmap_sem. |
| */ |
| ret = filemap_write_and_wait_range(inode->i_mapping, offset + len, |
| LLONG_MAX); |
| if (ret) |
| goto out_mmap; |
| truncate_pagecache(inode, ioffset); |
| |
| credits = ext4_writepage_trans_blocks(inode); |
| handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| goto out_mmap; |
| } |
| |
| down_write(&EXT4_I(inode)->i_data_sem); |
| ext4_discard_preallocations(inode); |
| |
| ret = ext4_es_remove_extent(inode, punch_start, |
| EXT_MAX_BLOCKS - punch_start); |
| if (ret) { |
| up_write(&EXT4_I(inode)->i_data_sem); |
| goto out_stop; |
| } |
| |
| ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1); |
| if (ret) { |
| up_write(&EXT4_I(inode)->i_data_sem); |
| goto out_stop; |
| } |
| ext4_discard_preallocations(inode); |
| |
| ret = ext4_ext_shift_extents(inode, handle, punch_stop, |
| punch_stop - punch_start, SHIFT_LEFT); |
| if (ret) { |
| up_write(&EXT4_I(inode)->i_data_sem); |
| goto out_stop; |
| } |
| |
| new_size = i_size_read(inode) - len; |
| i_size_write(inode, new_size); |
| EXT4_I(inode)->i_disksize = new_size; |
| |
| up_write(&EXT4_I(inode)->i_data_sem); |
| if (IS_SYNC(inode)) |
| ext4_handle_sync(handle); |
| inode->i_mtime = inode->i_ctime = ext4_current_time(inode); |
| ext4_mark_inode_dirty(handle, inode); |
| ext4_update_inode_fsync_trans(handle, inode, 1); |
| |
| out_stop: |
| ext4_journal_stop(handle); |
| out_mmap: |
| up_write(&EXT4_I(inode)->i_mmap_sem); |
| ext4_inode_resume_unlocked_dio(inode); |
| out_mutex: |
| inode_unlock(inode); |
| return ret; |
| } |
| |
| /* |
| * ext4_insert_range: |
| * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate. |
| * The data blocks starting from @offset to the EOF are shifted by @len |
| * towards right to create a hole in the @inode. Inode size is increased |
| * by len bytes. |
| * Returns 0 on success, error otherwise. |
| */ |
| int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len) |
| { |
| struct super_block *sb = inode->i_sb; |
| handle_t *handle; |
| struct ext4_ext_path *path; |
| struct ext4_extent *extent; |
| ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0; |
| unsigned int credits, ee_len; |
| int ret = 0, depth, split_flag = 0; |
| loff_t ioffset; |
| |
| /* |
| * We need to test this early because xfstests assumes that an |
| * insert range of (0, 1) will return EOPNOTSUPP if the file |
| * system does not support insert range. |
| */ |
| if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) |
| return -EOPNOTSUPP; |
| |
| /* Insert range works only on fs block size aligned offsets. */ |
| if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) || |
| len & (EXT4_CLUSTER_SIZE(sb) - 1)) |
| return -EINVAL; |
| |
| if (!S_ISREG(inode->i_mode)) |
| return -EOPNOTSUPP; |
| |
| trace_ext4_insert_range(inode, offset, len); |
| |
| offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb); |
| len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb); |
| |
| /* Call ext4_force_commit to flush all data in case of data=journal */ |
| if (ext4_should_journal_data(inode)) { |
| ret = ext4_force_commit(inode->i_sb); |
| if (ret) |
| return ret; |
| } |
| |
| inode_lock(inode); |
| /* Currently just for extent based files */ |
| if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { |
| ret = -EOPNOTSUPP; |
| goto out_mutex; |
| } |
| |
| /* Check for wrap through zero */ |
| if (inode->i_size + len > inode->i_sb->s_maxbytes) { |
| ret = -EFBIG; |
| goto out_mutex; |
| } |
| |
| /* Offset should be less than i_size */ |
| if (offset >= i_size_read(inode)) { |
| ret = -EINVAL; |
| goto out_mutex; |
| } |
| |
| /* Wait for existing dio to complete */ |
| ext4_inode_block_unlocked_dio(inode); |
| inode_dio_wait(inode); |
| |
| /* |
| * Prevent page faults from reinstantiating pages we have released from |
| * page cache. |
| */ |
| down_write(&EXT4_I(inode)->i_mmap_sem); |
| /* |
| * Need to round down to align start offset to page size boundary |
| * for page size > block size. |
| */ |
| ioffset = round_down(offset, PAGE_SIZE); |
| /* Write out all dirty pages */ |
| ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, |
| LLONG_MAX); |
| if (ret) |
| goto out_mmap; |
| truncate_pagecache(inode, ioffset); |
| |
| credits = ext4_writepage_trans_blocks(inode); |
| handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| goto out_mmap; |
| } |
| |
| /* Expand file to avoid data loss if there is error while shifting */ |
| inode->i_size += len; |
| EXT4_I(inode)->i_disksize += len; |
| inode->i_mtime = inode->i_ctime = ext4_current_time(inode); |
| ret = ext4_mark_inode_dirty(handle, inode); |
| if (ret) |
| goto out_stop; |
| |
| down_write(&EXT4_I(inode)->i_data_sem); |
| ext4_discard_preallocations(inode); |
| |
| path = ext4_find_extent(inode, offset_lblk, NULL, 0); |
| if (IS_ERR(path)) { |
| up_write(&EXT4_I(inode)->i_data_sem); |
| goto out_stop; |
| } |
| |
| depth = ext_depth(inode); |
| extent = path[depth].p_ext; |
| if (extent) { |
| ee_start_lblk = le32_to_cpu(extent->ee_block); |
| ee_len = ext4_ext_get_actual_len(extent); |
| |
| /* |
| * If offset_lblk is not the starting block of extent, split |
| * the extent @offset_lblk |
| */ |
| if ((offset_lblk > ee_start_lblk) && |
| (offset_lblk < (ee_start_lblk + ee_len))) { |
| if (ext4_ext_is_unwritten(extent)) |
| split_flag = EXT4_EXT_MARK_UNWRIT1 | |
| EXT4_EXT_MARK_UNWRIT2; |
| ret = ext4_split_extent_at(handle, inode, &path, |
| offset_lblk, split_flag, |
| EXT4_EX_NOCACHE | |
| EXT4_GET_BLOCKS_PRE_IO | |
| EXT4_GET_BLOCKS_METADATA_NOFAIL); |
| } |
| |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| if (ret < 0) { |
| up_write(&EXT4_I(inode)->i_data_sem); |
| goto out_stop; |
| } |
| } else { |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| } |
| |
| ret = ext4_es_remove_extent(inode, offset_lblk, |
| EXT_MAX_BLOCKS - offset_lblk); |
| if (ret) { |
| up_write(&EXT4_I(inode)->i_data_sem); |
| goto out_stop; |
| } |
| |
| /* |
| * if offset_lblk lies in a hole which is at start of file, use |
| * ee_start_lblk to shift extents |
| */ |
| ret = ext4_ext_shift_extents(inode, handle, |
| ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk, |
| len_lblk, SHIFT_RIGHT); |
| |
| up_write(&EXT4_I(inode)->i_data_sem); |
| if (IS_SYNC(inode)) |
| ext4_handle_sync(handle); |
| if (ret >= 0) |
| ext4_update_inode_fsync_trans(handle, inode, 1); |
| |
| out_stop: |
| ext4_journal_stop(handle); |
| out_mmap: |
| up_write(&EXT4_I(inode)->i_mmap_sem); |
| ext4_inode_resume_unlocked_dio(inode); |
| out_mutex: |
| inode_unlock(inode); |
| return ret; |
| } |
| |
| /** |
| * ext4_swap_extents - Swap extents between two inodes |
| * |
| * @inode1: First inode |
| * @inode2: Second inode |
| * @lblk1: Start block for first inode |
| * @lblk2: Start block for second inode |
| * @count: Number of blocks to swap |
| * @mark_unwritten: Mark second inode's extents as unwritten after swap |
| * @erp: Pointer to save error value |
| * |
| * This helper routine does exactly what is promise "swap extents". All other |
| * stuff such as page-cache locking consistency, bh mapping consistency or |
| * extent's data copying must be performed by caller. |
| * Locking: |
| * i_mutex is held for both inodes |
| * i_data_sem is locked for write for both inodes |
| * Assumptions: |
| * All pages from requested range are locked for both inodes |
| */ |
| int |
| ext4_swap_extents(handle_t *handle, struct inode *inode1, |
| struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2, |
| ext4_lblk_t count, int unwritten, int *erp) |
| { |
| struct ext4_ext_path *path1 = NULL; |
| struct ext4_ext_path *path2 = NULL; |
| int replaced_count = 0; |
| |
| BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem)); |
| BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem)); |
| BUG_ON(!inode_is_locked(inode1)); |
| BUG_ON(!inode_is_locked(inode2)); |
| |
| *erp = ext4_es_remove_extent(inode1, lblk1, count); |
| if (unlikely(*erp)) |
| return 0; |
| *erp = ext4_es_remove_extent(inode2, lblk2, count); |
| if (unlikely(*erp)) |
| return 0; |
| |
| while (count) { |
| struct ext4_extent *ex1, *ex2, tmp_ex; |
| ext4_lblk_t e1_blk, e2_blk; |
| int e1_len, e2_len, len; |
| int split = 0; |
| |
| path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE); |
| if (IS_ERR(path1)) { |
| *erp = PTR_ERR(path1); |
| path1 = NULL; |
| finish: |
| count = 0; |
| goto repeat; |
| } |
| path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE); |
| if (IS_ERR(path2)) { |
| *erp = PTR_ERR(path2); |
| path2 = NULL; |
| goto finish; |
| } |
| ex1 = path1[path1->p_depth].p_ext; |
| ex2 = path2[path2->p_depth].p_ext; |
| /* Do we have somthing to swap ? */ |
| if (unlikely(!ex2 || !ex1)) |
| goto finish; |
| |
| e1_blk = le32_to_cpu(ex1->ee_block); |
| e2_blk = le32_to_cpu(ex2->ee_block); |
| e1_len = ext4_ext_get_actual_len(ex1); |
| e2_len = ext4_ext_get_actual_len(ex2); |
| |
| /* Hole handling */ |
| if (!in_range(lblk1, e1_blk, e1_len) || |
| !in_range(lblk2, e2_blk, e2_len)) { |
| ext4_lblk_t next1, next2; |
| |
| /* if hole after extent, then go to next extent */ |
| next1 = ext4_ext_next_allocated_block(path1); |
| next2 = ext4_ext_next_allocated_block(path2); |
| /* If hole before extent, then shift to that extent */ |
| if (e1_blk > lblk1) |
| next1 = e1_blk; |
| if (e2_blk > lblk2) |
| next2 = e1_blk; |
| /* Do we have something to swap */ |
| if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS) |
| goto finish; |
| /* Move to the rightest boundary */ |
| len = next1 - lblk1; |
| if (len < next2 - lblk2) |
| len = next2 - lblk2; |
| if (len > count) |
| len = count; |
| lblk1 += len; |
| lblk2 += len; |
| count -= len; |
| goto repeat; |
| } |
| |
| /* Prepare left boundary */ |
| if (e1_blk < lblk1) { |
| split = 1; |
| *erp = ext4_force_split_extent_at(handle, inode1, |
| &path1, lblk1, 0); |
| if (unlikely(*erp)) |
| goto finish; |
| } |
| if (e2_blk < lblk2) { |
| split = 1; |
| *erp = ext4_force_split_extent_at(handle, inode2, |
| &path2, lblk2, 0); |
| if (unlikely(*erp)) |
| goto finish; |
| } |
| /* ext4_split_extent_at() may result in leaf extent split, |
| * path must to be revalidated. */ |
| if (split) |
| goto repeat; |
| |
| /* Prepare right boundary */ |
| len = count; |
| if (len > e1_blk + e1_len - lblk1) |
| len = e1_blk + e1_len - lblk1; |
| if (len > e2_blk + e2_len - lblk2) |
| len = e2_blk + e2_len - lblk2; |
| |
| if (len != e1_len) { |
| split = 1; |
| *erp = ext4_force_split_extent_at(handle, inode1, |
| &path1, lblk1 + len, 0); |
| if (unlikely(*erp)) |
| goto finish; |
| } |
| if (len != e2_len) { |
| split = 1; |
| *erp = ext4_force_split_extent_at(handle, inode2, |
| &path2, lblk2 + len, 0); |
| if (*erp) |
| goto finish; |
| } |
| /* ext4_split_extent_at() may result in leaf extent split, |
| * path must to be revalidated. */ |
| if (split) |
| goto repeat; |
| |
| BUG_ON(e2_len != e1_len); |
| *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth); |
| if (unlikely(*erp)) |
| goto finish; |
| *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth); |
| if (unlikely(*erp)) |
| goto finish; |
| |
| /* Both extents are fully inside boundaries. Swap it now */ |
| tmp_ex = *ex1; |
| ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2)); |
| ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex)); |
| ex1->ee_len = cpu_to_le16(e2_len); |
| ex2->ee_len = cpu_to_le16(e1_len); |
| if (unwritten) |
| ext4_ext_mark_unwritten(ex2); |
| if (ext4_ext_is_unwritten(&tmp_ex)) |
| ext4_ext_mark_unwritten(ex1); |
| |
| ext4_ext_try_to_merge(handle, inode2, path2, ex2); |
| ext4_ext_try_to_merge(handle, inode1, path1, ex1); |
| *erp = ext4_ext_dirty(handle, inode2, path2 + |
| path2->p_depth); |
| if (unlikely(*erp)) |
| goto finish; |
| *erp = ext4_ext_dirty(handle, inode1, path1 + |
| path1->p_depth); |
| /* |
| * Looks scarry ah..? second inode already points to new blocks, |
| * and it was successfully dirtied. But luckily error may happen |
| * only due to journal error, so full transaction will be |
| * aborted anyway. |
| */ |
| if (unlikely(*erp)) |
| goto finish; |
| lblk1 += len; |
| lblk2 += len; |
| replaced_count += len; |
| count -= len; |
| |
| repeat: |
| ext4_ext_drop_refs(path1); |
| kfree(path1); |
| ext4_ext_drop_refs(path2); |
| kfree(path2); |
| path1 = path2 = NULL; |
| } |
| return replaced_count; |
| } |